ARCH CAPITAL GROUP LTD., 10-Q filed on 8/5/2025
Quarterly Report
v3.25.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Aug. 01, 2025
Document and Entity Information [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-16209  
Entity Registrant Name ARCH CAPITAL GROUP LTD.  
Entity Incorporation, State or Country Code D0  
Entity Tax Identification Number 98-0374481  
Entity Address, Address Line One Waterloo House, Ground Floor  
Entity Address, Address Line Two 100 Pitts Bay Road,  
Entity Address, City or Town Pembroke  
Entity Address, Postal Zip Code HM 08,  
Entity Address, Country BM  
City Area Code (441)  
Local Phone Number 278-9250  
Entity Listings [Line Items]    
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   373,220,295
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2025  
Current Fiscal Year End Date --12-31  
Entity Central Index Key 0000947484  
Amendment Flag false  
Common shares    
Entity Listings [Line Items]    
Title of 12(b) Security Common shares, $0.0011 par value per share  
Trading Symbol ACGL  
Security Exchange Name NASDAQ  
Series F Depositary Share Equivalent    
Entity Listings [Line Items]    
Title of 12(b) Security Depositary shares, each representing a 1/1000th interest in a 5.45% Series F preferred share  
Trading Symbol ACGLO  
Security Exchange Name NASDAQ  
Series G Depositary Share Equivalent    
Entity Listings [Line Items]    
Title of 12(b) Security Depositary shares, each representing a 1/1000th interest in a 4.55% Series G preferred share  
Trading Symbol ACGLN  
Security Exchange Name NASDAQ  
v3.25.2
Unaudited Consolidated Balance Sheets - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Investments:    
Debt securities available for sale, at fair value $ 33,120 $ 29,819
Equity securities, at fair value 1,715 1,675
Other investments, at fair value 2,892 3,066
Investments accounted for using the equity method 6,566 5,980
Total investments 44,293 40,540
Cash 983 979
Accrued investment income 329 298
Investment in operating affiliates 1,356 1,240
Premiums receivable (net of allowance for credit losses: $46 and $45) 7,067 5,634
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses (net of allowance for credit losses: $19 and $17) 9,044 8,260
Contractholder receivables (net of allowance for credit losses: $6 and $5) 2,280 2,161
Ceded unearned premiums 3,229 2,428
Deferred acquisition costs 1,814 1,734
Receivable for securities sold 390 50
Goodwill and intangible assets 1,319 1,351
Other assets 6,684 6,231
Total assets 78,788 70,906
Liabilities    
Reserve for losses and loss adjustment expenses 32,089 29,369
Unearned premiums 11,625 10,218
Reinsurance balances payable 2,841 2,137
Contractholder payables 2,286 2,165
Collateral held for insured obligations 225 249
Senior notes 2,728 2,728
Payable for securities purchased 728 181
Other liabilities 3,225 3,039
Total liabilities 55,747 50,086
Commitments and contingencies (refer to Note 11)
Shareholders' Equity    
Non-cumulative preferred shares 830 830
Common shares ($0.0011 par, shares issued: 599.1 and 595.6) 1 1
Additional paid-in capital 2,660 2,510
Retained earnings 24,477 22,686
Accumulated other comprehensive income (loss), net of deferred income tax (48) (720)
Common shares held in treasury, at cost (shares: 223.7 and 219.2) (4,879) (4,487)
Total shareholders' equity available to Arch 23,041 20,820
Total liabilities and shareholders' equity 78,788 70,906
Fixed maturities available for sale, at fair value (amortized cost: $30,312 and $27,570; net of allowance for credit losses: $28 and $22)    
Investments:    
Debt securities available for sale, at fair value 30,332 27,035
Short-term investments available for sale, at fair value (amortized cost: $2,786 and $2,784; net of allowance for credit losses: $0 and $0)    
Investments:    
Debt securities available for sale, at fair value $ 2,788 $ 2,784
v3.25.2
Unaudited Consolidated Balance Sheets (Parentheticals) - USD ($)
shares in Millions, $ in Millions
Jun. 30, 2025
Dec. 31, 2024
Available for sale securities, amortized cost $ 33,098 $ 30,354
Allowance for credit losses on investments 28 22
Allowance for credit losses on premiums receivable 46 45
Allowance for credit losses on reinsurance recoverable 19 17
Allowance for credit losses on contractholder receivable $ 6 $ 5
Common shares, par value per share $ 0.0011 $ 0.0011
Common shares issued (shares) 599.1 595.6
Common shares held in treasury (shares) 223.7 219.2
Fixed maturities    
Available for sale securities, amortized cost $ 30,312 $ 27,570
Allowance for credit losses on investments 28 22
Short-term investments    
Available for sale securities, amortized cost 2,786 2,784
Allowance for credit losses on investments $ 0 $ 0
v3.25.2
Unaudited Consolidated Statements of Income - USD ($)
shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Revenues        
Net premiums earned $ 4,337 $ 3,565 $ 8,525 $ 6,987
Net investment income 405 364 783 691
Net realized gains (losses) 229 122 232 189
Other underwriting income 62 3 115 15
Equity in net income of investments accounted for using the equity method 162 167 215 266
Other income (loss) 18 8 16 22
Total revenues 5,213 4,229 9,886 8,170
Expenses        
Losses and loss adjustment expenses 2,303 1,827 4,890 3,555
Acquisition expenses 824 633 1,588 1,240
Other operating expenses 454 346 927 709
Corporate expenses 47 41 107 94
Amortization of intangible assets 48 27 97 48
Interest expense 38 35 73 69
Net foreign exchange (gains) losses 88 (1) 115 (32)
Total expenses 3,802 2,908 7,797 5,683
Income (loss) before income taxes and income (loss) from operating affiliates 1,411 1,321 2,089 2,487
Income tax (expense) benefit (214) (97) (335) (198)
Income (loss) from operating affiliates 40 45 57 100
Net income (loss) available to Arch 1,237 1,269 1,811 2,389
Preferred dividends (10) (10) (20) (20)
Net income (loss) available to Arch common shareholders $ 1,227 $ 1,259 $ 1,791 $ 2,369
Net income per common share and common share equivalent        
Basic (per share) $ 3.30 $ 3.38 $ 4.81 $ 6.37
Diluted (per share) $ 3.23 $ 3.30 $ 4.70 $ 6.22
Weighted average common shares and common share equivalents outstanding        
Basic (shares) 372.2 372.7 372.6 371.8
Diluted (shares) 379.9 381.6 380.8 380.9
v3.25.2
Unaudited Consolidated Statements of Comprehensive Income - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Comprehensive Income        
Net income (loss) $ 1,237 $ 1,269 $ 1,811 $ 2,389
Unrealized appreciation (decline) in value of available-for-sale investments:        
Unrealized holding gains (losses) arising during period 303 (26) 537 (167)
Reclassification of net realized (gains) losses, included in net income (loss) (7) 53 45 82
Foreign currency translation adjustments 64 (16) 90 (49)
Comprehensive income (loss) available to Arch $ 1,597 $ 1,280 $ 2,483 $ 2,255
v3.25.2
Unaudited Consolidated Statements of Changes in Shareholders' Equity - USD ($)
$ in Millions
Total
Non-cumulative preferred shares
Common shares
Additional paid-in capital
Retained earnings
Accumulated other comprehensive income (loss), net of deferred income tax
Unrealized appreciation (decline) in value of available-for-sale securities, net of deferred income tax
Foreign currency translation adjustments, net of deferred income tax
Common shares held in treasury, at cost
Balance at beginning of period at Dec. 31, 2023   $ 830 $ 1 $ 2,327 $ 20,295 $ (676) $ (565) $ (111) $ (4,424)
Amortization of share-based compensation       84          
Other changes       32          
Net income (loss) $ 2,389       2,389        
Preferred share dividends         (20)        
Unrealized holding gains (losses) during period, net of reclassification adjustment             (85)    
Foreign currency translation adjustments (49)             (49)  
Shares repurchased for treasury                 (39)
Balance at end of period at Jun. 30, 2024 20,665 830 1 2,443 22,664 (810) (650) (160) (4,463)
Balance at beginning of period at Mar. 31, 2024   830 1 2,401 21,405 (821) (677) (144) (4,461)
Amortization of share-based compensation       16          
Other changes       26          
Net income (loss) 1,269       1,269        
Preferred share dividends         (10)        
Unrealized holding gains (losses) during period, net of reclassification adjustment             27    
Foreign currency translation adjustments (16)             (16)  
Shares repurchased for treasury                 (2)
Balance at end of period at Jun. 30, 2024 20,665 830 1 2,443 22,664 (810) (650) (160) (4,463)
Balance at beginning of period at Dec. 31, 2024 20,820 830 1 2,510 22,686 (720) (507) (213) (4,487)
Amortization of share-based compensation       99          
Other changes       51          
Net income (loss) 1,811       1,811        
Preferred share dividends         (20)        
Unrealized holding gains (losses) during period, net of reclassification adjustment             582    
Foreign currency translation adjustments 90             90  
Shares repurchased for treasury                 (392)
Balance at end of period at Jun. 30, 2025 23,041 830 1 2,660 24,477 (48) 75 (123) (4,879)
Balance at beginning of period at Mar. 31, 2025   830 1 2,588 23,250 (408) (221) (187) (4,716)
Amortization of share-based compensation       25          
Other changes       47          
Net income (loss) 1,237       1,237        
Preferred share dividends         (10)        
Unrealized holding gains (losses) during period, net of reclassification adjustment             296    
Foreign currency translation adjustments 64             64  
Shares repurchased for treasury                 (163)
Balance at end of period at Jun. 30, 2025 $ 23,041 $ 830 $ 1 $ 2,660 $ 24,477 $ (48) $ 75 $ (123) $ (4,879)
v3.25.2
Unaudited Consolidated Statements of Cash Flows - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Operating Activities    
Net income (loss) $ 1,811 $ 2,389
Adjustments to reconcile net income (loss) to net cash provided by operating activities:    
Net realized (gains) losses (231) (196)
Equity in net (income) or loss of investments accounted for using the equity method and other income or loss (107) (174)
Amortization of intangible assets 97 48
Share-based compensation 99 84
Changes in:    
Reserve for losses and loss adjustment expenses, net of unpaid losses and loss adjustment expenses recoverable 1,386 1,369
Unearned premiums, net of ceded unearned premiums 338 879
Premiums receivable (1,294) (1,682)
Deferred acquisition costs 19 (80)
Reinsurance balances payable 663 616
Deferred income tax assets, net 109 45
Other items, net (308) (216)
Net cash provided by operating activities 2,582 3,082
Investing Activities    
Purchases of fixed maturity investments (17,568) (14,123)
Purchases of equity securities (987) (654)
Purchases of other investments (1,232) (1,369)
Proceeds from sales of fixed maturity investments 13,823 11,220
Proceeds from sales of equity securities 1,043 547
Proceeds from sales, redemptions and maturities of other investments 1,091 619
Proceeds from redemptions and maturities of fixed maturity investments 1,326 878
Net settlements of derivative instruments 240 12
Net (purchases) sales of short-term investments 52 (25)
Purchases of fixed assets (21) (26)
Other (3) 3
Net cash used for investing activities (2,236) (2,918)
Financing Activities    
Purchases of common shares under share repurchase program (359) 0
Proceeds from common shares issued, net 19 (8)
Common dividends paid (7) 0
Preferred dividends paid (20) (20)
Other (2) 0
Net cash used for financing activities (369) (28)
Effects of exchange rate changes on foreign currency cash and restricted cash 71 (7)
Increase (decrease) in cash and restricted cash 48 129
Cash and restricted cash, beginning of year 1,760 1,498
Cash and restricted cash, end of period 1,808 1,627
Income taxes paid (received) 149 145
Interest paid $ 64 $ 63
v3.25.2
Basis of Presentation and Recent Accounting Pronouncements
 6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Basis of Presentation and Recent Accounting Pronouncements
General
Arch Capital Group Ltd. (“Arch Capital”) is a publicly listed Bermuda exempted company which provides insurance, reinsurance and mortgage insurance on a worldwide basis through its wholly-owned subsidiaries. As used herein, the “Company” and/or “Arch” means Arch Capital and its subsidiaries.
Basis of Presentation
The interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All significant intercompany transactions and balances have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and assumptions. In the opinion of management, the accompanying unaudited interim consolidated financial statements reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of results on an interim basis. The results of any interim period are not necessarily indicative of the results for a full year or any future periods. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted; however, management believes that the disclosures are adequate to make the information presented not misleading. This report should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 (“2024 Form 10-K”), including the Company’s audited consolidated financial statements and related notes.
The Company has reclassified the presentation of certain prior year information to conform to the current presentation. Such reclassifications had no effect on the Company’s net income, comprehensive income, shareholders’ equity or cash flows. All amounts are in millions, except per share amounts, unless otherwise noted.
Recent Accounting Pronouncements
For information regarding additional accounting standards that the Company has not yet adopted, see note 3(t), “Significant Accounting Policies—Recent Accounting Pronouncements,” of the notes to consolidated financial statements in the Company’s 2024 Form 10-K.
v3.25.2
Acquisitions
 6 Months Ended
Jun. 30, 2025
Business Combination [Abstract]  
Acquisitions
On August 1, 2024, the Company completed the acquisition of the U.S MidCorp and Entertainment insurance business from Allianz (“MCE Acquisition”). This business is written by Fireman’s Fund Insurance Company, an affiliate of Allianz, and its subsidiaries (collectively, the “Business Entities”), in each case, relating to relevant policies with accident years 2016 and onwards (collectively, the “Business”), as well as certain assets of Allianz and its affiliates related to the Business. In connection with the acquisition of the Business, the Company also entered into certain reinsurance agreements relating to the Business and the Business Entities and other agreements providing for administration and other services for the Business Entities by the Company for the applicable policies being reinsured following the closing. The acquisition of the Business is an important part of the Company’s growth strategy, and provides a ballast to our existing insurance business. It further enhances the Company’s capabilities in the U.S. middle markets and represents an attractive way to enter a new niche entertainment insurance market.
Aggregate cash consideration for the transaction was $450 million. Direct costs related to the acquisition are immaterial, and were expensed as incurred. These include one-time costs that are directly attributable to third party consulting fees and other professional and legal fees related to the acquisition. Such costs are included within ‘corporate expenses’ in the consolidated statement of income. The Business acquired is included within the Company’s insurance segment beginning from the acquisition date.
The MCE Acquisition was accounted for as a business combination under FASB Accounting Standards Codification Topic 805, Business Combinations (“Topic 805”). Pursuant to Topic 805, the Company allocated the MCE Acquisition purchase price to tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date. The excess of the purchase price over those fair values was recorded to goodwill. During the measurement period, the Company adjusted the provisional amounts to reflect new information obtained about facts and circumstances that existed as of the Acquisition Date, which, if known, would have affected the measurement of the amounts recognized as of that date. Such adjustments impacted certain identifiable assets acquired and liabilities assumed, resulting in a decrease to net assets acquired and a corresponding increase to goodwill of $10 million. The Company completed the analysis of the fair value of the assets, liabilities assumed and the related allocation of the purchase price during the three month period ended June 30, 2025.
The following table summarizes the Company’s allocation of the purchase price to the acquired assets and liabilities assumed based on estimated fair values on August 1, 2024.
TotalUseful Life
Purchase price
Cash paid (a)$450 
Assets Acquired
Cash and investments, at fair value$2,332 
Premiums receivable, net of commissions224
Intangible asset -- distribution relationships22010 years
Intangible asset -- value of business acquired165
1-2 years
Intangible asset -- other (1)180
5-7 years
Other assets acquired175
Total assets acquired$3,296 
Liabilities Acquired
Reserves for losses and loss adjustment expenses $2,468 
Unearned premiums636
Other liabilities acquired18
Total liabilities acquired3,122 
Identifiable net assets acquired (b)$174 
Goodwill (a) - (b)$276 
(1)    Includes $130 million related to the net fair value adjustment to reserves for loss and loss adjustment expenses on August 1, 2024.
The Company recognized goodwill of $276 million that is primarily attributed to the expanded presence and long-term growth opportunities in the insurance market provided by this strategic acquisition. Approximately $565 million of the acquired goodwill and intangibles is expected to be deductible for income tax purposes. At the date of the acquisition, the Company established a net deferred tax asset of $24 million related to the estimated fair value of reserves for losses and loss adjustment expenses and unearned premiums.
Intangible assets resulting from the acquisition are amortized as part of ‘amortization of intangible assets’ in the Company’s consolidated statements of income. The significant fair value adjustments and related future amortization are as follows:
Value of business acquired (“VOBA”)— which represents the present value of the expected underwriting profit within the unearned premium liability, less costs to service the related policies and a risk premium. The fair value of VOBA was determined after taking into consideration certain key assumptions, including the estimated cost of capital, investment yield, loss ratio and related expenses.
Reserves for losses and loss adjustment expenses—to reflect a decrease related to the present value of the reserve for losses and loss adjustment expenses based on the estimated payout patterns, partially offset by an increase in losses and loss adjustment expenses related to the estimated market based risk margin. The risk margin represents the estimated costs of capital required by a market participant to assume the losses and loss adjustment expenses. The fair value of the reserve for losses and loss adjustment expenses was determined after taking into consideration certain key assumptions, including the estimated cost of capital, and investment yield.
Distribution relationships—the value of the distribution relationships was determined after taking into consideration certain key assumptions, including the estimated cost of capital, investment yield, retention rates, loss ratios, related expenses and effective tax rates that would impact the expected cash flows from Business policies written on a go forward basis.
The results of the acquired Business have been included in the Company’s consolidated financial statements beginning as of their acquisition date. It is impracticable to provide historical supplemental pro forma financial information along with revenue and earnings subsequent to the acquisition due to a variety of factors, including access to historical information and the operations of acquirees being integrated within the Company shortly after closing and not operating as discrete operations within the Company’s organizational structure.
v3.25.2
Share Transactions
 6 Months Ended
Jun. 30, 2025
Stockholders' Equity Note [Abstract]  
Share transactions
Share Repurchases
The Board of Directors of Arch Capital has authorized the investment in Arch Capital’s common shares through a share repurchase program. Since the inception of the share repurchase program, Arch Capital has repurchased 437.9 million common shares for an aggregate purchase price of $6.3 billion. For the six months ended June 30, 2025, Arch Capital repurchased 4.1 million shares under the share repurchase program with an aggregate purchase price of $359.7 million. Arch Capital did not repurchase any shares under the share repurchase program during the six months ended June 30, 2024. At June 30, 2025, $637.1 million of share repurchases were available under the program, which may be effected from time to time in open market or privately negotiated transactions. The timing and amount of the repurchase transactions under this program will depend on a variety of factors, including market conditions and corporate and regulatory considerations.
v3.25.2
Earnings Per Common Share
 6 Months Ended
Jun. 30, 2025
Earnings Per Share [Abstract]  
Earnings Per Common Share
The following table sets forth the computation of basic and diluted earnings per common share:
Three Months EndedSix Months Ended
June 30,June 30,
 2025202420252024
Numerator:
Net income (loss) available to Arch$1,237 $1,269 $1,811 $2,389 
Preferred dividends(10)(10)(20)(20)
Net income (loss) available to Arch common shareholders$1,227 $1,259 $1,791 $2,369 
Denominator:
Weighted average common shares and common share equivalents outstanding — basic372.2 372.7 372.6 371.8 
Effect of dilutive common share equivalents:
Nonvested restricted shares1.6 1.8 1.7 1.9 
Stock options (1)6.1 7.1 6.5 7.2 
Weighted average common shares and common share equivalents outstanding — diluted379.9 381.6 380.8 380.9 
Earnings per common share:
Basic$3.30 $3.38 $4.81 $6.37 
Diluted$3.23 $3.30 $4.70 $6.22 
(1)    Certain stock options were not included in the computation of diluted earnings per share where the exercise price of the stock options exceeded the average market price and would have been anti-dilutive or where, when applying the treasury stock method to in-the-money options, the sum of the proceeds, including unrecognized compensation, exceeded the average market price and would have been anti-dilutive. For the 2025 second quarter and 2024 second quarter, the number of stock options excluded were 2.2 million and 0.2 million, respectively. For the six months ended June 30, 2025 and 2024, the number of stock options excluded were 2.4 million and 0.4 million, respectively.
v3.25.2
Segment Information
 6 Months Ended
Jun. 30, 2025
Segment Reporting [Abstract]  
Segment Information
The Company’s insurance, reinsurance and mortgage segments each have managers who are responsible for the overall profitability of their respective segments and who are directly accountable to the Company’s chief operating decision makers (“CODM”). The Chief Executive Officer and the Chief Financial Officer and Treasurer are the Company’s CODMs. CODMs do not assess performance, measure return on equity or make resource allocation decisions on a line of business basis. Management measures segment performance for its three reportable segments based on underwriting income or loss. The Company does not manage its assets by segment, with the exception of goodwill and intangible assets, and accordingly, investment income is not allocated to each segment.
The Company determined its segments using the management approach described in accounting guidance regarding disclosures about segments of an enterprise and related information. The accounting policies of the segments are the same as those used for the preparation of the Company’s consolidated financial statements. Intersegment business is allocated to the segment accountable for the underwriting results.
The Company’s insurance segment primarily consists of commercial insurance lines of business, with a focus on specialty insurance products. These products are mainly offered in North America, Bermuda, the United Kingdom, continental Europe and Australia. Products offered in North America include: commercial automobile; commercial multi‐peril; other liability—claims made, which includes financial and professional lines; other liability—occurrence, which includes admitted and excess and surplus casualty lines; property and short-tail specialty; workers compensation; and other. Products offered across the Company’s International units include: property and short-tail specialty; and casualty and other.
The Company’s reinsurance segment offers reinsurance products on a worldwide basis. Product lines of business include: casualty; marine and aviation; specialty; property catastrophe; property excluding property catastrophe; and other.
The Company’s mortgage segment consists of U.S. primary mortgage insurance business written predominantly on loans sold to the Federal National Mortgage Association (“Fannie Mae”) and the Federal Home Loan Mortgage Corporation (“Freddie Mac”), each a government sponsored entity (“GSE”) and also through non GSE approved entities (combined “Arch MI U.S.”); reinsurance and underwriting services related to U.S. credit-risk transfer (“CRT”) business which are predominately with the GSEs and other U.S. mortgage reinsurance transactions; and international mortgage insurance and reinsurance business covering loans primarily in Australia and Europe.
The Company’s results also include net investment income, net realized gains or losses (which includes realized and unrealized changes in the fair value of equity securities and assets accounted for using the fair value option, realized and unrealized gains or losses on derivative instruments, changes in the allowance for credit losses on financial assets and gains or losses realized from the acquisition or disposition of subsidiaries), equity in net income or loss of investments accounted for using the equity method, other income (loss), corporate expenses, transaction costs and other, amortization of intangible assets, interest expense, net foreign exchange gains or losses, income tax items, income or loss from operating affiliates and items related to the Company’s non-cumulative preferred shares.
The following tables summarize the Company’s underwriting income or loss by segment, together with a reconciliation of underwriting income or loss to net income available to Arch common shareholders:
Three Months Ended
June 30, 2025
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$2,681 $3,196 $323 $6,196 
Premiums ceded (1)(645)(1,137)(70)(1,848)
Net premiums written2,036 2,059 253 4,348 
Change in unearned premiums(67)28 28 (11)
Net premiums earned1,969 2,087 281 4,337 
Other underwriting income (2)13 46 3 62 
Losses and loss adjustment expenses(1,178)(1,128)3 (2,303)
Acquisition expenses(387)(436)(1)(824)
Other operating expenses (3)(288)(118)(48)(454)
Underwriting income (loss)$129 $451 $238 818 
Net investment income405 
Net realized gains (losses)229 
Equity in net income of investments accounted for using the equity method162 
Other income (loss)18 
Corporate expenses (4)(29)
Transaction costs and other (4)(18)
Amortization of intangible assets(48)
Interest expense(38)
Net foreign exchange gains (losses)(88)
Income (loss) before income taxes and income (loss) from operating affiliates1,411 
Income tax (expense) benefit(214)
Income (loss) from operating affiliates40 
Net income (loss) available to Arch1,237 
Preferred dividends(10)
Net income (loss) available to Arch common shareholders$1,227 
Underwriting Ratios
Loss ratio59.8 %54.1 %(1.2)%53.1 %
Acquisition expense ratio19.6 %20.9 %0.4 %19.0 %
Other operating expense ratio (5)14.0 %3.5 %16.0 %9.1 %
Combined ratio93.4 %78.5 %15.2 %81.2 %
Goodwill and intangible assets$875 $105 $339 $1,319 
(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other underwriting income’ includes revenue earned from underwriting-related activities covered under existing service contracts.
(3)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(4)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
(5)    The ‘Other operating expense ratio’ for the 2025 period includes ‘Other underwriting income.’
Three Months Ended
June 30, 2024
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$2,102 $2,941 $340 $5,382 
Premiums ceded (1)(544)(994)(64)(1,601)
Net premiums written1,558 1,947 276 3,781 
Change in unearned premiums(80)(167)31 (216)
Net premiums earned1,478 1,780 307 3,565 
Other underwriting income— 1 2 3 
Losses and loss adjustment expenses(848)(1,006)27 (1,827)
Acquisition expenses(288)(345)— (633)
Other operating expenses (2)(233)(64)(49)(346)
Underwriting income (loss)$109 $366 $287 762 
Net investment income364 
Net realized gains (losses)122 
Equity in net income of investments accounted for using the equity method167 
Other income (loss)8 
Corporate expenses (3)(23)
Transaction costs and other (3)(18)
Amortization of intangible assets(27)
Interest expense(35)
Net foreign exchange gains (losses)1 
Income (loss) before income taxes and income (loss) from operating affiliates1,321 
Income tax (expense) benefit(97)
Income (loss) from operating affiliates45 
Net income (loss) available to Arch1,269 
Preferred dividends(10)
Net income (loss) available to Arch common shareholders$1,259 
Underwriting Ratios    
Loss ratio57.3 %56.5 %(8.6)%51.2 %
Acquisition expense ratio19.5 %19.4 %0.1 %17.8 %
Other operating expense ratio15.8 %3.6 %15.9 %9.7 %
Combined ratio92.6 %79.5 %7.4 %78.7 %
Goodwill and intangible assets$255 $114 $356 $725 

(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(3)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
Six Months Ended
June 30, 2025
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$5,326 $6,690 $649 $12,659 
Premiums ceded (1)(1,357)(2,315)(130)(3,796)
Net premiums written3,969 4,375 519 8,863 
Change in unearned premiums(140)(260)62 (338)
Net premiums earned3,829 4,115 581 8,525 
Other underwriting income (2)16 85 14 115 
Losses and loss adjustment expenses(2,406)(2,484)— (4,890)
Acquisition expenses(730)(853)(5)(1,588)
Other operating expenses (3)(582)(245)(100)(927)
Underwriting income (loss)$127 $618 $490 1,235 
Net investment income783 
Net realized gains (losses)232 
Equity in net income of investments accounted for using the equity method215 
Other income (loss)16 
Corporate expenses (4)(79)
Transaction costs and other (4)(28)
Amortization of intangible assets(97)
Interest expense(73)
Net foreign exchange gains (losses)(115)
Income (loss) before income taxes and income (loss) from operating affiliates2,089 
Income tax (expense) benefit(335)
Income (loss) from operating affiliates57 
Net income (loss) available to Arch1,811 
Preferred dividends(20)
Net income (loss) available to Arch common shareholders$1,791 
Underwriting Ratios
Loss ratio62.8 %60.4 %— %57.4 %
Acquisition expense ratio19.1 %20.7 %0.9 %18.6 %
Other operating expense ratio (5)14.8 %3.9 %14.9 %9.5 %
Combined ratio96.7 %85.0 %15.8 %85.5 %
(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other underwriting income’ includes revenue earned from underwriting-related activities covered under existing service contracts.
(3)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(4)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
(5)    The ‘Other operating expense ratio’ for the 2025 period includes ‘Other underwriting income.’
Six Months Ended
June 30, 2024
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$4,228 $6,408 $681 $11,315 
Premiums ceded (1)(1,128)(2,195)(128)(3,449)
Net premiums written3,100 4,213 553 7,866 
Change in unearned premiums(171)(767)59 (879)
Net premiums earned2,929 3,446 612 6,987 
Other underwriting income— 3 12 15 
Losses and loss adjustment expenses(1,702)(1,889)36 (3,555)
Acquisition expenses(564)(676)— (1,240)
Other operating expenses (2)(468)(139)(102)(709)
Underwriting income (loss)$195 $745 $558 1,498 
Net investment income691 
Net realized gains (losses)189 
Equity in net income of investments accounted for using the equity method266 
Other income (loss)22 
Corporate expenses (3)(69)
Transaction costs and other (3)(25)
Amortization of intangible assets(48)
Interest expense(69)
Net foreign exchange gains (losses)32 
Income (loss) before income taxes and income (loss) from operating affiliates2,487 
Income tax (expense) benefit(198)
Income (loss) from operating affiliates100 
Net income (loss) available to Arch2,389 
Preferred dividends(20)
Net income (loss) available to Arch common shareholders$2,369 
Underwriting Ratios
Loss ratio58.1 %54.8 %(5.8)%50.9 %
Acquisition expense ratio19.2 %19.6 %0.1 %17.7 %
Other operating expense ratio16.0 %4.0 %16.7 %10.1 %
Combined ratio93.3 %78.4 %11.0 %78.7 %
(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(3)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
v3.25.2
Reserve for Losses and Loss Adjustment Expenses
 6 Months Ended
Jun. 30, 2025
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]  
Reserve for losses and loss adjustment expenses
The following table represents an analysis of losses and loss adjustment expenses and a reconciliation of the beginning and ending reserve for losses and loss adjustment expenses:
Three Months EndedSix Months Ended
June 30,June 30,
2025202420252024
Reserve for losses and loss adjustment expenses at beginning of period
$30,946 $23,705 $29,369 $22,752 
Unpaid losses and loss adjustment expenses recoverable
8,379 7,069 7,821 6,690 
Net reserve for losses and loss adjustment expenses at beginning of period
22,567 16,636 21,548 16,062 
Net incurred losses and loss adjustment expenses relating to losses occurring in:
Current year
2,456 1,948 5,240 3,800 
Prior years
(153)(121)(350)(245)
Total net incurred losses and loss adjustment expenses
2,303 1,827 4,890 3,555 
Net losses and loss adjustment expense reserves of acquired businesses (1) 50 50 50 50 
Net foreign exchange (gains) losses and other
400 (10)593 (94)
Net paid losses and loss adjustment expenses relating to losses occurring in:
Current year
(424)(193)(865)(285)
Prior years
(1,320)(927)(2,640)(1,905)
Total net paid losses and loss adjustment expenses
(1,744)(1,120)(3,505)(2,190)
Net reserve for losses and loss adjustment expenses at end of period
23,576 17,383 23,576 17,383 
Unpaid losses and loss adjustment expenses recoverable
8,513 7,083 8,513 7,083 
Reserve for losses and loss adjustment expenses at end of period
$32,089 $24,466 $32,089 $24,466 
(1)     Activity in the 2025 periods related to the MCE Acquisition (see note 2). Activity in the 2024 periods related to the acquisition of RMIC Companies, Inc. and its wholly-owned subsidiaries that, together, comprise the run-off mortgage insurance business of Old Republic International Corporation.
Prior year development (“PYD”) arises from changes in loss estimates during the current period related to events occurring in prior calendar years. Long-tailed lines include lines of business that typically take many years for claims to settle such as third-party liability; short-tailed lines are those that settle more quickly such as property. The table below summarizes (favorable) and adverse net PYD by segment and tail length:
Three Months EndedSix Months Ended
(Favorable) AdverseJune 30,June 30,
2025Short-tailedLong-tailedTotalShort-tailedLong-tailedTotal
Insurance$(13)$5 $(8)$(28)$3 $(25)
Reinsurance(75)(6)(81)(202)2 (200)
Mortgage(64)— (64)(125)— (125)
Total$(152)$(1)$(153)$(355)$5 $(350)
2024
Insurance$(13)$8 $(5)$(30)$15 $(15)
Reinsurance(48)14 (34)(91)17 (74)
Mortgage(82)— (82)(156)— (156)
Total$(143)$22 $(121)$(277)$32 $(245)
2025 Second Quarter
The insurance segment’s short-tailed lines included $7 million of favorable development in travel and accident, primarily from the 2024 accident year (i.e., the year in which a loss occurred). Long-tailed lines included $14 million of adverse development in programs business, primarily from the 2018 and 2023 accident years.
The reinsurance segment’s short-tailed lines included $60 million of favorable development from property other than property catastrophe business, primarily from the 2023 and 2024 underwriting years (i.e., all premiums and losses attributable to contracts having an inception or renewal date within the given 12 month period). Long-tailed lines included $6 million of favorable development, primarily from the 2022 to 2023 underwriting years.
The mortgage segment’s favorable development was driven by reductions on reserves for delinquent loans associated with the U.S. first lien portfolio from the 2024 accident year, with the credit risk transfer and international businesses also contributing.
2024 Second Quarter
The insurance segment’s short-tailed lines included $20 million of favorable development in surety business, primarily from the 2007 accident year, partially offset by $15 million of adverse development in property, energy, marine and aviation business, primarily from the 2022 accident year. Long-tailed lines included $9 million of adverse development in programs business, primarily from the 2022 and 2023 accident years.
The reinsurance segment’s short-tailed lines included $30 million of favorable development related to property other than property catastrophe business, primarily from the 2022 and 2023 underwriting years. Long-tailed lines included $14 million of adverse development in casualty, primarily from the 2020 and 2021 underwriting years.
The mortgage segment’s favorable development was driven by reserve releases associated with the U.S. first lien portfolio from the 2023 accident year, with the credit risk transfer and international businesses also contributing to the favorable development.
Six Months Ended June 30, 2025
The insurance segment’s short-tailed lines included $15 million of favorable development in travel and accident, primarily from the 2023 and 2024 accident years, and $11 million of favorable development in property, energy, marine and aviation, primarily from the 2024 accident year.
The reinsurance segment’s short-tailed lines included $89 million of favorable development from property other than property catastrophe business and $86 million of favorable development from property catastrophe, primarily from the 2023 and 2024 underwriting years for both lines.
The mortgage segment’s favorable development was driven by reserve releases associated with the U.S. first lien portfolio from the 2024 accident year, with the credit risk transfer and international businesses also contributed to the favorable development.
Six Months Ended June 30, 2024
The insurance segment’s short-tailed lines included $25 million of favorable development surety business, primarily from the 2007 and 2022 accident years. Long-tailed lines included $17 million of adverse development in programs business, primarily from the 2020 to 2023 accident years.
The reinsurance segment’s short-tailed lines included $51 million of favorable development from property other than property catastrophe business, primarily from the 2022 and 2023 underwriting years and $37 million of favorable development from other specialty business, primarily from the 2021 and 2022 underwriting years. Long-tailed lines included $17 million of adverse development in casualty, primarily from the 2017 underwriting year.
The mortgage segment’s favorable development was driven by reserve releases associated with the U.S. first lien portfolio from the 2022 to 2023 accident years, with the credit risk transfer and international businesses also contributing to the favorable development.
v3.25.2
Allowance for Expected Credit Losses
 6 Months Ended
Jun. 30, 2025
Credit Loss [Abstract]  
Allowance for expected credit losses
Premiums Receivable
The following table provides a roll forward of the allowance for expected credit losses of the Company’s premium receivables:
Premium Receivables, Net of AllowanceAllowance for Expected Credit Losses
Three Months Ended June 30, 2025
Balance at beginning of period$6,607 $43 
Change for provision of expected credit losses (1) 3 
Balance at end of period$7,067 $46 
Three Months Ended June 30, 2024
Balance at beginning of period$5,765 $32 
Change for provision of expected credit losses (1) 4 
Balance at end of period$6,268 $36 
Six Months Ended June 30, 2025
Balance at beginning of year$5,634 $45 
Change for provision of expected credit losses (1) 1 
Balance at end of period$7,067 $46 
Six Months Ended June 30, 2024
Balance at beginning of year$4,644 $34 
Change for provision of expected credit losses (1)
2 
Balance at end of period$6,268 $36 

(1)    Amounts deemed uncollectible are written-off in operating expenses. For the 2025 second quarter and 2024 second quarter, amounts written off were $1 million and nil, respectively. For the six months ended June 30, 2025 and 2024 period, amounts written off were $1 million and nil, respectively.
Reinsurance Recoverables
The following table provides a roll forward of the allowance for expected credit losses of the Company’s reinsurance recoverables:
Reinsurance Recoverables, Net of AllowanceAllowance for Expected Credit Losses
Three Months Ended June 30, 2025
Balance at beginning of period$8,969 $17 
Change for provision of expected credit losses2 
Balance at end of period$9,044 $19 
Three Months Ended June 30, 2024
Balance at beginning of period$7,509 $16 
Change for provision of expected credit losses4 
Balance at end of period$7,473 $20 
Six Months Ended June 30, 2025
Balance at beginning of year$8,260 $17 
Change for provision of expected credit losses2 
Balance at end of period$9,044 $19 
Six Months Ended June 30, 2024
Balance at beginning of year$7,064 $21 
Change for provision of expected credit losses(1)
Balance at end of period$7,473 $20 
The following table summarizes the Company’s reinsurance recoverables on paid and unpaid losses (not including ceded unearned premiums):
June 30,
December 31,
20252024
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses$9,044$8,260
% due from carriers with A.M. Best rating of “A-” or better62.5 %63.8 %
% due from all other carriers with no A.M. Best rating (1)37.5 %36.2 %
Largest balance due from any one carrier as % of total shareholders’ equity7.9 %7.8 %
(1)    At June 30, 2025 and December 31, 2024 over 95% of such amount were collateralized through reinsurance trusts, funds withheld arrangements, letters of credit or other.

Contractholder Receivables
The following table provides a roll forward of the allowance for expected credit losses of the Company’s contractholder receivables:
Contract-holder Receivables, Net of AllowanceAllowance for Expected Credit Losses
Three Months Ended June 30, 2025
Balance at beginning of period$2,212 $6 
Change for provision of expected credit losses— 
Balance at end of period$2,280 $6 
Three Months Ended June 30, 2024
Balance at beginning of period$1,907 $3 
Change for provision of expected credit losses1 
Balance at end of period2,016 $4 
Six Months Ended June 30, 2025
Balance at beginning of year$2,161 $5 
Change for provision of expected credit losses1 
Balance at end of period$2,280 $6 
Six Months Ended June 30, 2024
Balance at beginning of year$1,814 $3 
Change for provision of expected credit losses1 
Balance at end of period2,016 $4 
v3.25.2
Investment Information
 6 Months Ended
Jun. 30, 2025
Disclosure Investment Information [Abstract]  
Investment
Available For Sale Investments
The following table summarizes the fair value and cost or amortized cost of the Company’s securities classified as available for sale:
Estimated
Fair
Value		Gross
Unrealized
Gains		Gross
Unrealized
Losses		Allowance for Expected Credit Losses Cost or
Amortized
Cost
June 30, 2025
Fixed maturities:
Corporate bonds$14,429 $273 $(218)$(16)$14,390 
U.S. government and government agencies6,585 38 (48)— 6,595 
Asset backed securities2,770 18 (20)(10)2,782 
Non-U.S. government securities3,149 82 (70)(2)3,139 
Commercial mortgage backed securities838 7 (7)— 838 
Residential mortgage backed securities2,386 24 (24)— 2,386 
Municipal bonds175 — (7)— 182 
Total30,332 442 (394)(28)30,312 
Short-term investments2,788 3 (1)— 2,786 
Total$33,120 $445 $(395)$(28)$33,098 
December 31, 2024
Fixed maturities:
Corporate bonds$12,487 $110 $(346)$(12)$12,735 
U.S. government and government agencies6,710 8 (149)— 6,851 
Asset backed securities2,900 19 (32)(8)2,921 
Non-U.S. government securities2,538 30 (107)(1)2,616 
Commercial mortgage backed securities1,058 6 (11)(1)1,064 
Residential mortgage backed securities1,079 6 (31)— 1,104 
Municipal bonds263 — (16)— 279 
Total27,035 179 (692)(22)27,570 
Short-term investments2,784 2 (2)— 2,784 
Total$29,819 $181 $(694)$(22)$30,354 
The following table summarizes, for all available for sale securities in an unrealized loss position, the fair value and gross unrealized loss by length of time the security has been in a continual unrealized loss position:
 Less than 12 Months12 Months or MoreTotal
Estimated
Fair
Value		Gross
Unrealized
Losses		Estimated
Fair
Value		Gross
Unrealized
Losses		Estimated
Fair
Value		Gross
Unrealized
Losses
June 30, 2025
Fixed maturities:
Corporate bonds$1,944 $(83)$2,043 $(135)$3,987 $(218)
U.S. government and government agencies1,727 (29)308 (19)2,035 (48)
Non-U.S. government securities1,132 (25)395 (45)1,527 (70)
Residential mortgage backed securities158 (3)175 (21)333 (24)
Asset backed securities497 (4)348 (16)845 (20)
Commercial mortgage backed securities276 (2)188 (5)464 (7)
Municipal bonds15 — 147 (7)162 (7)
Total5,749 (146)3,604 (248)9,353 (394)
Short-term investments394 (1)— — 394 (1)
Total$6,143 $(147)$3,604 $(248)$9,747 $(395)
December 31, 2024
Fixed maturities:
Corporate bonds$4,582 $(114)$2,924 $(232)$7,506 $(346)
U.S. government and government agencies5,130 (100)516 (49)5,646 (149)
Non-U.S. government securities1,650 (58)418 (49)2,068 (107)
Residential mortgage backed securities571 (6)186 (25)757 (31)
Asset backed securities236 (8)426 (24)662 (32)
Commercial mortgage backed securities180 (1)434 (10)614 (11)
Municipal bonds48 (1)176 (15)224 (16)
Total12,397 (288)5,080 (404)17,477 (692)
Short-term investments97 (2)— — 97 (2)
Total$12,494 $(290)$5,080 $(404)$17,574 $(694)
At June 30, 2025, on a lot level basis, approximately 6,560 security lots out of a total of approximately 23,600 security lots were in an unrealized loss position and the largest single unrealized loss from a single lot in the Company’s fixed maturity portfolio was $4 million. At December 31, 2024, on a lot level basis, approximately 9,980 security lots out of a total of approximately 20,930 security lots were in an unrealized loss position and the largest single unrealized loss from a single lot in the Company’s fixed maturity portfolio was $8 million.
The contractual maturities of the Company’s fixed maturities are shown in the following table. Expected maturities, which are management’s best estimates, will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
June 30, 2025December 31, 2024
MaturityEstimated
Fair
Value		Amortized
Cost		Estimated
Fair
Value		Amortized
Cost
Due in one year or less$480 $490 $438 $451 
Due after one year through five years17,031 16,947 15,364 15,590 
Due after five years through 10 years6,123 6,168 5,811 6,039 
Due after 10 years704 701 385 401 
 24,338 24,306 21,998 22,481 
Residential mortgage backed securities2,386 2,386 1,079 1,104 
Commercial mortgage backed securities838 838 1,058 1,064 
Asset backed securities2,770 2,782 2,900 2,921 
Total$30,332 $30,312 $27,035 $27,570 
Equity Securities, at Fair Value
At June 30, 2025, the Company held $1.7 billion of equity securities, at fair value, compared to $1.7 billion at December 31, 2024. Such holdings include publicly traded common stocks, primarily in the consumer cyclical and non-cyclical, technology, communication and financial sectors, and exchange-traded funds in fixed income, equity and other sectors.
Other Investments, at Fair Value
The following table summarizes the Company’s other investments:
June 30,
2025		December 31,
2024
Other investments$1,810 $2,135 
Fixed maturities 1,009 854 
Short term investments68 70 
Equity securities5 7 
Total$2,892 $3,066 
The following table summarizes the Company’s other investments, as detailed in the previous table, by strategy:
June 30,
2025		December 31,
2024
Investment grade fixed income$1,029 $1,055 
Private equity252 229 
Lending238 303 
Term loan investments217 430 
Credit related funds72 99 
Energy2 19 
Total$1,810 $2,135 
Net Investment Income
The components of net investment income were derived from the following sources:
June 30,
 20252024
Three Months Ended
Fixed maturities$360 $306 
Short term investments24 35 
Equity securities10 10 
Other (1)35 35 
Gross investment income429 386 
Investment expenses(24)(22)
Net investment income$405 $364 
Six Months Ended
Fixed maturities$702 $586 
Short term investments50 64 
Equity securities21 18 
Other (1)63 68 
Gross investment income836 736 
Investment expenses(53)(45)
Net investment income$783 $691 
(1)    Amounts include dividends and other distributions on investment funds, term loan investments, funds held balances, cash balances and other items.

Net Realized Gains (Losses)
Net realized gains (losses), which include changes in the allowance for credit losses on financial assets and net impairment losses recognized in earnings were as follows:
June 30,
 20252024
Three Months Ended
Available for sale securities:  
Gross gains on investment sales$69 $13 
Gross losses on investment sales(56)(77)
Change in fair value of assets and liabilities accounted for using the fair value option:
Fixed maturities20 (4)
Other investments(11)(28)
Short-term investments3 — 
Equity securities, at fair value:
Net realized gains (losses) on sales during the period7 5 
Net unrealized gains (losses) on equity securities still held at reporting date129 7 
Allowance for credit losses:
Investments related(8)4 
Underwriting related(2)(3)
Derivative instruments (1)163 1 
Other (2)(85)204 
Net realized gains (losses)$229 $122 
Six Months Ended
Available for sale securities:
Gross gains on investment sales$120 $63 
Gross losses on investment sales(169)(155)
Change in fair value of assets and liabilities accounted for using the fair value option:
Fixed maturities22 (2)
Other investments2 (30)
Short-term investments3 — 
Equity securities, at fair value:
Net realized gains (losses) on sales during the period54 16 
Net unrealized gains (losses) on equity securities still held at reporting date34 89 
Allowance for credit losses:
Investments related(8)(2)
Underwriting related(1)(2)
Derivative instruments (1)262 (9)
Other (2)(87)221 
Net realized gains (losses)$232 $189 
(1)    See note 10 for information on the Company’s derivative instruments.
(2)    Amounts in the 2025 periods primarily include losses related to the anticipated sale of certain alternative investments accounted for under the equity method.
Investments Accounted For Using the Equity Method
The following table summarizes the Company’s investments accounted for using the equity method, by strategy:
June 30,
2025		December 31,
2024
Private equity$2,101 $1,915 
Credit related funds1,637 1,487 
Lending850 616 
Real estate837 869 
Fixed income462 384 
Infrastructure417 425 
Equities215 217 
Energy47 67 
Total$6,566 $5,980 
Certain of the Company’s other investments are in investment funds for which the Company has the option to redeem at agreed upon values as described in each investment fund’s subscription agreement. Depending on the terms of the various subscription agreements, investments in investment funds may be redeemed daily, monthly, quarterly or on other terms. Two common redemption restrictions that may impact the Company’s ability to redeem these investment funds are gates and lockups. A gate is a suspension of redemptions that may be implemented by the general partner or investment manager of the fund in order to defer, in whole or in part, the redemption request in the event the aggregate amount of redemption requests exceeds a predetermined percentage of the investment fund’s net assets and which may otherwise hinder the general partner or investment manager’s ability to liquidate holdings in an orderly fashion in order to generate the cash necessary to fund extraordinarily large redemption payouts. A lockup period is the initial amount of time an investor is contractually required to hold the security before having the ability to redeem. If the investment funds are eligible to be redeemed, the time to redeem such fund can take weeks or months following the notification.
Limited Partnership Interests
In the normal course of its activities, the Company invests in limited partnerships as part of its overall investment strategy. Such amounts are included in ‘investments accounted for using the equity method’ and ‘investments accounted for using the fair value option.’ The Company has determined that it is not required to consolidate these investments because it is not the primary beneficiary of the funds. The Company’s maximum exposure to loss with respect to these investments is limited to the investment carrying amounts reported in the Company’s consolidated balance sheet and any unfunded commitment.
The following table summarizes investments in limited partnership interests where the Company has a variable interest by balance sheet line item:
June 30,
2025		December 31,
2024
Investments accounted for using the equity method (1)$6,566 $5,980 
Investments accounted for using the fair value option (2)32 48 
Total$6,598 $6,028 
(1)    Aggregate unfunded commitments were $4.2 billion at June 30, 2025, compared to $4.3 billion at December 31, 2024.
(2)    Aggregate unfunded commitments were $22 million at June 30, 2025, compared to $21 million at December 31, 2024.
Equity in Net Income (Loss) of Investments Accounted for Using the Equity Method
Income from investment funds accounted for using the equity method for the 2025 second quarter was $162 million, compared to $167 million for the 2024 second quarter and an income of $215 million for the six months ended June 30, 2025, compared to income of $266 million for the six months ended June 30, 2024. In applying the equity method, investments are initially recorded at cost and are subsequently adjusted based on the Company’s proportionate share of the net income or loss of the funds (which include changes in the market value of the underlying securities in the funds). Such investments are generally recorded on a one to three month lag based on the availability of reports from the investment funds.
Investments in Operating Affiliates
Investments in which the Company has significant influence over the operating and financial policies are classified as ‘investments in operating affiliates’ on the Company’s balance sheets and are accounted for under the equity method. Such investments primarily include the Company’s investment in Coface SA (“Coface”), Greysbridge Holdings Ltd. (“Greysbridge”), and Premia Holdings Ltd. Investments in Coface and Premia Holdings Ltd. are generally recorded on a three month lag, while the Company’s investment in Greysbridge is not recorded on a lag.
As of June 30, 2025, the Company owned approximately 29.9% of the issued shares of Coface, or 30% excluding treasury shares, with a carrying value of $654 million, compared to $592 million at December 31, 2024.
As of June 30, 2025, the Company owned 40% of Greysbridge with a carrying value of $582 million, compared to $523 million at December 31, 2024.
Income from operating affiliates for the 2025 second quarter was $40 million, compared to $45 million for the 2024 second quarter and income of $57 million for the six months ended June 30, 2025, compared to income of $100 million for six months ended June 30, 2024.
See note 16 for information on Company’s transactions with related parties.

Allowance for Expected Credit Losses
The following table provides a roll forward of the allowance for expected credit losses of the Company’s securities classified as available for sale:
Structured Securities (1)Corporate
Bonds		Non-U.S.
Government
Securities		Total
Three Months Ended June 30, 2025
Balance at beginning of period$8 $12 $1 $21 
Additions for current-period provision for expected credit losses— 2 — 2 
Additions (reductions) for previously recognized expected credit losses 2 4 1 7 
Reductions due to disposals— (2)— (2)
Balance at end of period$10 $16 $2 $28 
Three Months Ended June 30, 2024
Balance at beginning of period$7 $24 $1 $32 
Additions for current-period provision for expected credit losses— — — — 
Additions (reductions) for previously recognized expected credit losses 3 (6)— (3)
Reductions due to disposals— (2)— (2)
Balance at end of period$10 $16 $1 $27 
Six Months Ended June 30, 2025
Balance at beginning of year$9 $12 $1 $22 
Additions for current-period provision for expected credit losses3 2 — 5 
Additions (reductions) for previously recognized expected credit losses(2)5 1 4 
Reductions due to disposals— (3)— (3)
Balance at end of period$10 $16 $2 $28 
Six Months Ended June 30, 2024
Balance at beginning of year$7 $20 $1 $28 
Additions for current-period provision for expected credit losses— — — — 
Additions (reductions) for previously recognized expected credit losses3 (1)— 2 
Reductions due to disposals— (3)— (3)
Balance at end of period$10 $16 $1 $27 
(1)    Includes asset backed securities, residential mortgage backed securities and commercial mortgage backed securities.
Restricted Assets
The Company is required to maintain assets on deposit, which primarily consist of fixed maturities, with various regulatory authorities to support its underwriting operations. The Company’s subsidiaries maintain assets in trust accounts as collateral for transactions with affiliated companies and also have investments in segregated portfolios primarily to provide collateral or guarantees for letters of credit to third parties. See note 18, “Commitments and Contingencies,” of the notes to consolidated financial statements in the Company’s 2024 Form 10-K.
The following table details the value of the Company’s restricted assets:
June 30,
2025		December 31,
2024
Assets used for collateral or guarantees:  
Affiliated transactions$5,229 $4,730 
Third party agreements6,512 5,999 
Deposits with U.S. regulatory authorities955 882 
Other (1)1,515 1,437 
Total restricted assets$14,211 $13,048 
(1)    Primarily includes Funds at Lloyds, deposits with non-U.S. regulatory authorities and other restricted assets.
Reconciliation of Cash and Restricted Cash
The following table details reconciliation of cash and restricted cash within the Consolidated Balance Sheets:
June 30,
2025		December 31,
2024
Cash$983 $979 
Restricted cash (included in ‘other assets’)825 781 
Cash and restricted cash$1,808 $1,760 
v3.25.2
Fair Value
 6 Months Ended
Jun. 30, 2025
Fair Value Disclosures [Abstract]  
Fair Value
Accounting guidance regarding fair value measurements addresses how companies should measure fair value when they are required to use a fair value measure for recognition or disclosure purposes under GAAP and provides a common definition of fair value to be used throughout GAAP. It defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly fashion between market participants at the measurement date. In addition, it establishes a three-level valuation hierarchy for the disclosure of fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. The level in the hierarchy within which a given fair value measurement falls is determined based on the lowest level input that is significant to the measurement (Level 1 being the highest priority and Level 3 being the lowest priority).
The levels in the hierarchy are defined as follows:
Level 1:
Inputs to the valuation methodology are observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets
Level 2:
Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument
Level 3:
Inputs to the valuation methodology are unobservable and significant to the fair value measurement
The following is a description of the valuation methodologies used for securities measured at fair value, as well as the general classification of such securities pursuant to the valuation hierarchy. The Company reviews its securities measured at fair value and discusses the proper classification of such investments with investment advisers and others.
The Company determines the existence of an active market based on its judgment as to whether transactions for the financial instrument occur in such market with sufficient frequency and volume to provide reliable pricing information. The independent pricing sources obtain market quotations and actual transaction prices for securities that have quoted prices in active markets. The Company uses quoted values and other data provided by nationally recognized independent pricing sources as inputs into its process for determining fair values of its fixed maturity investments. To validate the techniques or models used by pricing sources, the Company's review process includes, but is not limited to: (i) quantitative analysis (e.g., comparing the quarterly return for each managed portfolio to its target benchmark, with significant differences identified and investigated); (ii) a review of the average number of prices obtained in the pricing process and the range of resulting fair values; (iii) initial and ongoing evaluation of methodologies used by outside parties to calculate fair value; (iv) a comparison of the fair value estimates to the Company’s knowledge of the current market; (v) a comparison of the pricing services' fair values to other pricing services' fair values for the same investments; and (vi) periodic back-testing, which includes randomly selecting purchased or sold securities and comparing the executed prices to the fair value estimates from the pricing service. A price source hierarchy was maintained in order to determine which price source would be used (i.e., a price obtained from a pricing service with more seniority in the hierarchy will be used over a less senior one in all cases). The hierarchy prioritizes pricing services based on availability and reliability and assigns the highest priority to index providers. Based on the above review, the Company will challenge any prices for a security or portfolio which are considered not to be representative of fair value. The Company did not adjust any of the prices obtained from the independent pricing sources at June 30, 2025.
In certain circumstances, when fair values are unavailable from these independent pricing sources, quotes are obtained directly from broker-dealers who are active in the corresponding markets. Such quotes are subject to the validation procedures noted above. Where quotes are unavailable, fair value is determined by the Investment Manager using quantitative and qualitative assessments such as internally modeled values. Of the $38.2 billion of financial assets and liabilities measured at fair value at June 30, 2025, approximately $257 million, or 0.7%, were priced using non-binding broker-dealer quotes or modeled valuations. Of the $35.0 billion of financial assets and liabilities measured at fair value at December 31, 2024, approximately $185 million, or 0.5%, were priced using non-binding broker-dealer quotes or modeled valuations.
Fixed maturities
The Company uses the market approach valuation technique to estimate the fair value of its fixed maturity securities, when possible. The market approach includes obtaining prices from independent pricing services, such as index providers and pricing vendors, as well as to a lesser extent quotes from broker-dealers. The independent pricing sources obtain market quotations and actual transaction prices for securities that have quoted prices in active markets. Each source has its own proprietary method for determining the fair value of securities that are not actively traded. In general, these methods involve the use of “matrix pricing” in which the independent pricing source uses observable market inputs including, but not limited to, investment yields, credit risks and spreads, benchmarking of like securities, broker-dealer quotes, reported trades and sector groupings to determine a reasonable fair value.
The following describes the significant inputs generally used to determine the fair value of the Company’s fixed maturity securities by asset class:
U.S. government and government agencies – valuations provided by independent pricing services, with all prices provided through index providers and pricing vendors. The Company determined that all U.S. Treasuries would be classified as Level 1 securities due to observed levels of trading activity, the high number of strongly correlated pricing quotes received on U.S. Treasuries and other factors. The fair values of U.S. government agency securities are generally determined using the spread above the risk-free yield curve. As the yields for the risk-free yield curve and the spreads for these securities are observable market inputs, the fair values of U.S. government agency securities are classified within Level 2.
Corporate bonds – valuations provided by independent pricing services, substantially all through index providers and pricing vendors with a small amount through broker-dealers. The fair values of these securities are generally determined using the spread above the risk-free yield curve. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. As the significant inputs used in the pricing process for corporate bonds are observable market inputs, the fair value of these securities are classified within Level 2. A small number of securities are included in Level 3 due to a low level of transparency on the inputs used in the pricing process.
Municipal bonds – valuations provided by independent pricing services, with all prices provided through index providers and pricing vendors. The fair values of these securities are generally determined using spreads obtained from broker-dealers who trade in the relevant security market, trade prices and the new issue market. As the
significant inputs used in the pricing process for municipal bonds are observable market inputs, the fair value of these securities are classified within Level 2.
Residential mortgage-backed securities – valuations provided by independent pricing services, substantially all through pricing vendors and index providers with a small amount through broker-dealers. The fair values of these securities are generally determined through the use of pricing models (including Option Adjusted Spread) which use spreads to determine the expected average life of the securities. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. The pricing services also review prepayment speeds and other indicators, when applicable. As the significant inputs used in the pricing process for mortgage-backed securities are observable market inputs, the fair value of these securities are classified within Level 2. A small number of securities are included in Level 3 due to a low level of transparency on the inputs used in the pricing process.
Commercial mortgage-backed securities – valuations provided by independent pricing services, substantially all through index providers and pricing vendors with a small amount through broker-dealers. The fair values of these securities are generally determined through the use of pricing models which use spreads to determine the appropriate average life of the securities. These spreads are generally obtained from the new issue market, secondary trading and from broker-dealers who trade in the relevant security market. The pricing services also review prepayment speeds and other indicators, when applicable. As the significant inputs used in the pricing process for commercial mortgage-backed securities are observable market inputs, the fair value of these securities are classified within Level 2.
Non-U.S. government securities – valuations provided by independent pricing services, with all prices provided through index providers and pricing vendors. The fair values of these securities are generally based on international indices or valuation models which include daily observed yield curves, cross-currency basis index spreads and country credit spreads. As the significant inputs used in the pricing process for non-U.S. government securities are observable market inputs, the fair value of these securities are classified within Level 2.
Asset-backed securities – valuations provided by independent pricing services, substantially all through index providers and pricing vendors with a small amount through broker-dealers. The fair values of these securities are generally determined through the use of pricing models (including Option Adjusted Spread) which use spreads to determine the appropriate average life of the securities. These spreads are generally obtained from the new issue
market, secondary trading and from broker-dealers who trade in the relevant security market. The pricing services also review prepayment speeds and other indicators, when applicable. As the significant inputs used in the pricing process for asset-backed securities are observable market inputs, the fair value of these securities are classified within Level 2.
Equity securities
The Company determined that exchange-traded equity securities would be included in Level 1 as their fair values are based on quoted market prices in active markets. Certain equity securities are included in Level 2 of the valuation hierarchy as the significant inputs used in the pricing process for such securities are observable market inputs. Other equity securities are included in Level 3 due to the lack of an available independent price source for such securities. As the significant inputs used to price these securities are unobservable, the fair value of such securities are classified as Level 3.
Other investments
The Company’s other investments include term loan investments for which fair values are estimated by using quoted prices of term loan investments with similar characteristics, pricing models or matrix pricing. Such investments are generally classified within Level 2. The fair values for certain of the Company’s other investments are determined using net asset values as advised by external fund managers. The net asset value is based on the fund manager’s valuation of the underlying holdings in accordance with the fund’s governing documents. In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. A small number of securities are included in Level 3 due to the lack of an available independent price source for such securities.
Derivative instruments
The Company’s futures contracts, foreign currency forward contracts, interest rate swaps and other derivatives trade in the over-the-counter derivative market. The Company uses the market approach valuation technique to estimate the fair value for these derivatives based on significant observable market inputs from third party pricing vendors, non-binding broker-dealer quotes and/or recent trading activity. As the significant inputs used in the pricing process for these derivative instruments are observable market inputs, the fair value of these securities are classified within Level 2.

Short-term investments
The Company determined that certain of its short-term investments held in highly liquid money market-type funds, U.S. Treasury bills and commercial paper would be included in Level 1 as their fair values are based on quoted market prices in active markets. The fair values of certain short-term investments are generally determined using the spread above the risk-free yield curve and are classified within Level 2. Other short-term investments are included in Level 3 due to the lack of an available independent price source for such securities. As the significant inputs used to price these short-term securities are unobservable, the fair value of such securities are classified as Level 3.
Residential mortgage loans
The Company’s residential mortgage loans (included in ‘other assets’ in the consolidated balance sheets) include amounts related to the Company’s whole mortgage loan purchase and sell program. Fair values of residential mortgage loans are generally determined based on market prices. As significant inputs used in the pricing process for these residential mortgage loans are observable market inputs, the fair value of these securities are classified within Level 2.
Other liabilities
The Company’s other liabilities include contingent and deferred consideration liabilities related to the Company’s acquisitions. Contingent consideration liabilities are remeasured at fair value at each balance sheet date with changes in fair value recognized in ‘net realized gains (losses’). To determine the fair value of contingent consideration liabilities, the Company estimates the future payments using an income approach based on modeled inputs which include a weighted average cost of capital. Deferred consideration liabilities are measured at fair value on the transaction date. The Company determined that contingent and deferred consideration liabilities would be included within Level 3.

The following table presents the Company’s financial assets and liabilities measured at fair value by level at June 30, 2025:
  Estimated Fair Value Measurements Using:
 Estimated
Fair
Value		Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)		Significant
Other
Observable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets measured at fair value:    
Available for sale securities:    
Fixed maturities:    
Corporate bonds$14,429 $— $14,284 $145 
U.S. government and government agencies6,585 6,585 — — 
Asset backed securities2,770 — 2,753 17 
Non-U.S. government securities3,149 — 3,149 — 
Commercial mortgage backed securities838 — 838 — 
Residential mortgage backed securities2,386 — 2,386 — 
Municipal bonds175 — 175 — 
Total30,332 6,585 23,585 162 
Short-term investments2,788 2,735 53 — 
Equity securities, at fair value1,715 1,680 27 8 
Derivative instruments (2)271 — 271 — 
Residential mortgage loans27 — 27 — 
Fair value option:
Corporate bonds988 — 988 — 
Non-U.S. government securities15 — 15 — 
U.S. government and government agencies6 6 — — 
Short-term investments68 6 17 45 
Equity securities5 — — 5 
Other investments423 — 215 208 
Other investments measured at net asset value (1)1,387 
Total2,892 12 1,235 258 
Total assets measured at fair value$38,025 $11,012 $25,198 $428 
Liabilities measured at fair value:    
Other liabilities$(20)$— $— $(20)
Derivative instruments (2)(159)— (159)— 
Total liabilities measured at fair value$(179)$— $(159)$(20)

(1)    In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
(2)    See note 10.
The following table presents the Company’s financial assets and liabilities measured at fair value by level at December 31, 2024:
  Estimated Fair Value Measurements Using:
 Estimated
Fair
Value		Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)		Significant
Other
Observable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets measured at fair value:
Available for sale securities:
Fixed maturities:
Corporate bonds$12,487 $— $12,390 $97 
U.S. government and government agencies6,710 6,709 1 — 
Asset backed securities2,900 — 2,900 — 
Non-U.S. government securities2,538 — 2,538 — 
Commercial mortgage backed securities1,058 — 1,058 — 
Residential mortgage backed securities1,079 — 1,079 — 
Municipal bonds263 — 263 — 
Total27,035 6,709 20,229 97 
Short-term investments2,784 2,704 80 — 
Equity securities, at fair value1,675 1,640 28 7 
Derivative instruments (2)206 — 206 — 
Residential mortgage loans15 — 15 — 
Fair value option:
Corporate bonds832 — 832 — 
Non-U.S. government securities8 — 8 — 
Asset backed securities— — — — 
U.S. government and government agencies14 14 — — 
Short-term investments70 — 37 33 
Equity securities6 2 — 4 
Other investments752 — 563 189 
Other investments measured at net asset value (1)1,383 
Total3,065 16 1,440 226 
Total assets measured at fair value$34,780 $11,069 $21,998 $330 
Liabilities measured at fair value:
Other liabilities$(73)$— $— $(73)
Derivative instruments (2)(115)— (115)— 
Total liabilities measured at fair value$(188)$— $(115)$(73)

(1)    In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
(2)    See note 10.
The following table presents a reconciliation of the beginning and ending balances for all financial assets and liabilities measured at fair value on a recurring basis using Level 3 inputs:
AssetsLiabilities
sAvailable For SaleFair Value OptionFair Value
 Structured Securities (1)Corporate
Bonds		Short-term
Investments		Other
Investments		Short-term
Investments		Equity
Securities		Equity
Securities		Other Liabilities
Three Months Ended June 30, 2025  
Balance at beginning of period$— $150 $— $206 $29 $4 $7 $(34)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — — — 1 — — 
Included in other comprehensive income— — — — — — — (2)
Purchases, issuances, sales and settlements
Purchases14 — — 44 18 — 1 — 
Issuances— — — — — — — — 
Sales— — — (3)— — — — 
Settlements(2)(5)— (39)(2)— — 16 
Transfers in and/or out of Level 35 — — — — — — — 
Balance at end of period$17 $145 $— $208 $45 $5 $8 $(20)
Three Months Ended June 30, 2024  
Balance at beginning of period$— $160 $97 $126 $17 $4 $5 $(22)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — — — — — — 
Included in other comprehensive income— — — — — — — — 
Purchases, issuances, sales and settlements
Purchases— — — 30 3 — 1 — 
Issuances— — — — — — — (13)
Sales — — — (2)— — — — 
Settlements— — — (10)(6)— — — 
Transfers in and/or out of Level 3— — — — — — — — 
Balance at end of period$— $160 $97 $144 $14 $4 $6 $(35)
Six Months Ended June 30, 2025  
Balance at beginning of year$— $97 $— $189 $33 $4 $7 $(73)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — — — 1 — 2 
Included in other comprehensive income— — — — — — — (2)
Purchases, issuances, sales and settlements
Purchases14 — — 96 24 — 1 — 
Issuances— — — — — — — — 
Sales — — — (3)— — — — 
Settlements(2)(22)— (74)(12)— — 53 
Transfers in and/or out of Level 35 70 — — — — — — 
Balance at end of period$17 $145 $— $208 $45 $5 $8 $(20)
Six Months Ended June 30, 2024  
Balance at beginning of year$— $147 $84 $106 $10 $4 $5 $(22)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — (4)— — — (1)
Included in other comprehensive income— 2 1 — — — — 1 
Purchases, issuances, sales and settlements
Purchases— 98 12 60 10 — 1 — 
Issuances— — — — — — — (13)
Sales— — — (2)— — — — 
Settlements— (87)— (16)(6)— — — 
Transfers in and/or out of Level 3— — — — — — — — 
Balance at end of period$— $160 $97 $144 $14 $4 $6 $(35)
(1)     Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities.
(2)     Gains or losses were included in net realized gains (losses).
Financial Instruments Disclosed, But Not Carried, At Fair Value
The Company uses various financial instruments in the normal course of its business. The carrying values of cash, accrued investment income, receivable for securities sold, certain other assets, payable for securities purchased and certain other liabilities approximated their fair values at June 30, 2025, due to their respective short maturities. As these financial instruments are not actively traded, their respective fair values are classified within Level 2.
At June 30, 2025, the Company’s senior notes were carried at their cost, net of debt issuance costs, of $2.7 billion and had a fair value of $2.5 billion. At December 31, 2024, the Company’s senior notes were carried at their cost, net of debt issuance costs, of $2.7 billion and had a fair value of $2.4 billion. The fair values of the senior notes were obtained from a third party pricing service and are based on observable market inputs. As such, the fair values of the senior notes are classified within Level 2.
v3.25.2
Derivative Instruments
 6 Months Ended
Jun. 30, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Derivative Instruments
The Company’s investment strategy allows for the use of derivative instruments. The Company’s derivative instruments are recorded on its consolidated balance sheets at fair value. The Company utilizes exchange traded U.S. Treasury notes, Eurodollar and other futures contracts and commodity futures to manage portfolio duration or replicate investment positions in its portfolios and the Company routinely utilizes foreign currency forward contracts, currency options, index futures contracts and other derivatives as part of its total return objective. In addition, certain of the Company’s investments are managed in portfolios which incorporate the use of foreign currency forward contracts which are intended to provide an economic hedge against foreign currency movements. 
From time to time, the Company purchases to-be-announced mortgage backed securities (“TBAs”) as part of its investment strategy. TBAs represent commitments to purchase a future issuance of agency mortgage backed securities. For the period between purchase of a TBA and issuance of the underlying security, the Company’s position is accounted for as a derivative. The Company purchases TBAs in both long and short positions to enhance investment performance and as part of its overall investment strategy.
The following table summarizes information on the fair values and notional values of the Company’s derivative instruments:
 Estimated Fair Value
 Asset Derivatives (1)Liability Derivatives (1)Notional
Value (2)
June 30, 2025
Futures contracts$110 $(11)$8,208 
Foreign currency forward contracts92 (62)2,123 
Other (3)69 (86)2,073 
Total$271 $(159)
December 31, 2024
Futures contracts$78 $(46)$4,781 
Foreign currency forward contracts90 (48)1,698 
Other (3)38 (21)236 
Total$206 $(115)
(1)    The fair value of asset derivatives are included in ‘other assets’ and the fair value of liability derivatives are included in ‘other liabilities.’
(2)    Represents the absolute notional value of all outstanding contracts, consisting of long and short positions.
(3)    Includes swaps, options and other derivatives contracts.

The Company did not hold any derivatives that were designated as hedging instruments at June 30, 2025 or December 31, 2024.
The Company’s derivative instruments can be traded under master netting agreements, which establish terms that apply to all derivative transactions with a counterparty. In the event of a bankruptcy or other stipulated event of default, such agreements provide that the non-defaulting party may elect to terminate all outstanding derivative transactions, in which case all individual derivative positions (loss or gain) with a counterparty are closed out and netted and replaced with a single amount, usually referred to as the termination amount, which is expressed in a single currency. The resulting single net amount, where positive, is payable to the party “in-the-money” regardless of whether or not it is the defaulting party, unless the parties have agreed that only the non-defaulting party is entitled to receive a termination payment where the net amount is positive and is in its favor. Contractual close-out netting reduces derivative credit exposure from gross to net exposure.
At June 30, 2025, asset derivatives and liability derivatives of $271 million and $159 million, respectively, were subject to a master netting agreement, compared to $206 million and $115 million, respectively, at December 31, 2024.
Realized and unrealized contract gains or losses on the Company’s derivative instruments are reflected in ‘net realized gains (losses)’ in the consolidated statements of income, as summarized in the following table:
Derivatives not designated asJune 30,
hedging instruments:20252024
Three Months Ended
Net realized gains (losses):
Futures contracts$93 $(3)
Foreign currency forward contracts53 2 
Other (1)17 2 
Total$163 $1 
Six Months Ended
Net realized gains (losses):
Futures contracts$139 $(17)
Foreign currency forward contracts83 1 
Other (1)40 7 
Total$262 $(9)
(1)    Includes realized gains or losses on swaps, options and other derivatives contracts.
v3.25.2
Commitments and Contingencies
 6 Months Ended
Jun. 30, 2025
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies
Investment Commitments
The Company’s investment commitments, which are primarily related to agreements entered into by the Company to invest in funds and separately managed accounts when called upon, were approximately $4.3 billion at June 30, 2025, compared to $4.4 billion at December 31, 2024.
Interest Paid
Interest paid on the Company’s senior notes and other borrowings was $64 million for the six months ended June 30, 2025, compared to $63 million for the 2024 period.
v3.25.2
Variable Interest Entities
 6 Months Ended
Jun. 30, 2025
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]  
Variable Interest Entity Disclosure
Bellemeade Re
The Company has entered into aggregate excess of loss mortgage reinsurance agreements with various special purpose reinsurance companies domiciled in Bermuda (the “Bellemeade Agreements”). At the time the Bellemeade Agreements were entered into, the applicability of the accounting guidance that addresses VIEs was evaluated. As a result of the evaluation of the Bellemeade Agreements, the Company concluded that these entities are VIEs. However, given that the ceding insurers do not have the unilateral power to direct those activities that are significant to their economic performance, the Company does not consolidate such entities in its consolidated financial statements. The reinsurance premium paid in regard to the Bellemeade Agreements is calculated by multiplying the outstanding reinsurance coverage amount at the beginning of the period by the coupon rate, which is the SOFR plus a contractual risk margin, less the actual investment income collected during the preceding month on the assets included in the underlying reinsurance trusts. In the event the assets included in the underlying reinsurance trusts became severely impaired or worthless and the special purpose reinsurance companies were unable to meet their future obligations, the Company’s mortgage insurance subsidiaries would be liable to fulfill claim payments to policyholders. The Company’s maximum exposure to loss associated with these VIEs is determined as the amount of mortgage insurance claim payments on the insured policies, net of aggregate reinsurance payments previously received, up to the full aggregate excess of loss reinsurance coverage amounts.
The following table summarizes the total assets of the Bellemeade entities:
June 30,
2025		December 31, 2024
Bellemeade Entities
(Issue Date)		Total VIE AssetsCoverage Remaining from Reinsurers (1)Total VIE
Assets
2021-3 Ltd. (Sep-21)205 19 363 
2022-1 Ltd. (Jan-22)59 14 202 
2022-2 Ltd. (Sep-22)53 100 180 
2023-1 Ltd. (Oct-23)174 44 186 
2024-1 Ltd. (Aug-24)163 41 163 
Total $654 $218 $1,094 
(1)     Coverage from a separate panel of reinsurers remaining at June 30, 2025.
v3.25.2
Other Comprehensive Income (Loss)
 6 Months Ended
Jun. 30, 2025
Comprehensive Income Note Disclosure [Abstract]  
Other Comprehensive Income (Loss)
The following tables present details about amounts reclassified from accumulated other comprehensive income and the tax effects allocated to each component of other comprehensive income (loss):
Amounts Reclassified from AOCI
Consolidated Statement of IncomeThree Months EndedSix Months Ended
Details AboutLine Item That IncludesJune 30,June 30,
AOCI ComponentsReclassification2025202420252024
Unrealized appreciation (decline) on available-for-sale investments
Net realized gains (losses)$14 $(64)$(49)$(92)
Provision for credit losses(8)4 (8)(2)
Total before tax6 (60)(57)(94)
Income tax (expense) benefit1 7 12 12 
Net of tax$7 $(53)$(45)$(82)
Before Tax AmountTax Expense (Benefit)Net of Tax Amount
Three Months Ended June 30, 2025
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$304 $1 $303 
Less reclassification of net realized gains (losses) included in net income6 (1)7 
Foreign currency translation adjustments62 (2)64 
Other comprehensive income (loss)$360 $— $360 
Three Months Ended June 30, 2024
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$(36)$(10)$(26)
Less reclassification of net realized gains (losses) included in net income(60)(7)(53)
Foreign currency translation adjustments(16)— (16)
Other comprehensive income (loss)$8 $(3)$11 
Six Months Ended June 30, 2025
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$549 $12 $537 
Less reclassification of net realized gains (losses) included in net income(57)(12)(45)
Foreign currency translation adjustments88 (2)90 
Other comprehensive income (loss)$694 $22 $672 
Six Months Ended June 30, 2024
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$(187)$(20)$(167)
Less reclassification of net realized gains (losses) included in net income(94)(12)(82)
Foreign currency translation adjustments(49)— (49)
Other comprehensive income (loss)$(142)$(8)$(134)
v3.25.2
Income Taxes
 6 Months Ended
Jun. 30, 2025
Income Tax Disclosure [Abstract]  
Income Taxes
The Company’s income tax provision on income before income taxes, including income (loss) from operating affiliates, resulted in an effective tax rate of 15.6% for the six months ended June 30, 2025, compared to 7.7% for the six months ended June 30, 2024. The year-over-year increase is primarily attributed to the Government of Bermuda enacting the Corporate Income Tax Act 2023, which established a 15% corporate income tax effective January 1, 2025. The Company’s effective tax rate, which is based upon the expected annual effective tax rate, may fluctuate from period to period based on the relative mix of income or loss reported by jurisdiction and the varying tax rates in each jurisdiction.
The Company had a net deferred tax asset of $1.5 billion at June 30, 2025, compared to a net deferred tax asset of $1.6 billion at December 31, 2024. In addition, the Company paid $149 million of income taxes for the six months ended June 30, 2025, compared to $145 million of income taxes paid for the six months ended June 30, 2024
v3.25.2
Legal Proceedings
 6 Months Ended
Jun. 30, 2025
Disclosure Legal Proceedings [Abstract]  
Legal Proceedings
The Company, in common with the insurance industry in general, is subject to litigation and arbitration in the normal course of its business. As of June 30, 2025, the Company was not a party to any litigation or arbitration which is expected by management to have a material adverse effect on the Company’s results of operations and financial condition and liquidity.
v3.25.2
Transactions With Related Parties
 6 Months Ended
Jun. 30, 2025
Related Party Transactions [Abstract]  
Transactions with related parties
Premia Reinsurance Ltd. is a multi-line Bermuda reinsurance company (and its affiliates together with Premia Holdings Ltd., “Premia”). The Company has entered into certain reinsurance transactions with Premia. During the six months ended June 30, 2025 and 2024, the Company did not enter into any new reinsurance transactions with Premia. At June 30, 2025, the Company recorded a funds held asset from Premia of $127 million, compared to $137 million at December 31, 2024.
Somers Group Holdings Ltd. and its wholly owned subsidiaries (collectively, “Somers”) are wholly owned by Greysbridge. For the six months ended June 30, 2025, the Company’s net premiums written was reduced by $419 million, compared to $428 million for the six months ended June 30, 2024, as a result of certain reinsurance transactions with Somers. In addition, Somers paid certain acquisition costs and administrative fees to the Company. At June 30, 2025, the Company recorded a reinsurance recoverable on unpaid and paid losses from Somers of $1.8 billion and a reinsurance balance payable to Somers of $602 million, compared to $1.6 billion and $489 million, respectively, at December 31, 2024.
Under the terms of the Greysbridge equity financing, beginning January 1, 2024, the Company has a call right (but not the obligation) and Warburg and Kelso each have a put right (but not the obligation) to buy/sell a certain amount of their initial shares annually at the current year-end tangible book value per share of Greysbridge. In 2024, Warburg and Kelso both delivered a put option notice to sell a certain amount of their initial shares. This transaction, which will involve third-party purchasers of such shares, is expected to close in the 2025 calendar year, subject to any required regulatory approvals and other closing conditions. In association with the put option notice at June 30, 2025, the Company’s balance sheet reflected $290 million in both other assets and other liabilities.
v3.25.2
Subsequent Events
 6 Months Ended
Jun. 30, 2025
Subsequent Events [Abstract]  
Subsequent Event
Share Repurchases
From July 1 to August 5, 2025, the Company repurchased approximately 2.8 million common shares for an aggregate purchase price of $244 million. At August 5, 2025, approximately $393 million of repurchases were available under the Company’s share repurchase program.
v3.25.2
Pay vs Performance Disclosure - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Pay vs Performance Disclosure        
Net income available to Arch $ 1,237 $ 1,269 $ 1,811 $ 2,389
v3.25.2
Insider Trading Arrangements
 3 Months Ended
Jun. 30, 2025
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.25.2
Basis of Presentation and Recent Accounting Pronouncements (Policies)
 6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Basis of accounting The interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). All significant intercompany transactions and balances have been eliminated in consolidation.
Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and assumptions. In the opinion of management, the accompanying unaudited interim consolidated financial statements reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of results on an interim basis. The results of any interim period are not necessarily indicative of the results for a full year or any future periods.
Reclassification of prior periods The Company has reclassified the presentation of certain prior year information to conform to the current presentation. Such reclassifications had no effect on the Company’s net income, comprehensive income, shareholders’ equity or cash flows.
Recent accounting pronouncements For information regarding additional accounting standards that the Company has not yet adopted, see note 3(t), “Significant Accounting Policies—Recent Accounting Pronouncements,” of the notes to consolidated financial statements in the Company’s 2024 Form 10-K
v3.25.2
Acquisitions (Tables)
 6 Months Ended
Jun. 30, 2025
Business Combination [Abstract]  
Allocation of purchase price to acquired assets and liabilities
The following table summarizes the Company’s allocation of the purchase price to the acquired assets and liabilities assumed based on estimated fair values on August 1, 2024.
TotalUseful Life
Purchase price
Cash paid (a)$450 
Assets Acquired
Cash and investments, at fair value$2,332 
Premiums receivable, net of commissions224
Intangible asset -- distribution relationships22010 years
Intangible asset -- value of business acquired165
1-2 years
Intangible asset -- other (1)180
5-7 years
Other assets acquired175
Total assets acquired$3,296 
Liabilities Acquired
Reserves for losses and loss adjustment expenses $2,468 
Unearned premiums636
Other liabilities acquired18
Total liabilities acquired3,122 
Identifiable net assets acquired (b)$174 
Goodwill (a) - (b)$276 
(1)    Includes $130 million related to the net fair value adjustment to reserves for loss and loss adjustment expenses on August 1, 2024.
v3.25.2
Earnings Per Common Share (Tables)
 6 Months Ended
Jun. 30, 2025
Earnings Per Share [Abstract]  
Schedule of computation of basic and diluted earnings per common share
The following table sets forth the computation of basic and diluted earnings per common share:
Three Months EndedSix Months Ended
June 30,June 30,
 2025202420252024
Numerator:
Net income (loss) available to Arch$1,237 $1,269 $1,811 $2,389 
Preferred dividends(10)(10)(20)(20)
Net income (loss) available to Arch common shareholders$1,227 $1,259 $1,791 $2,369 
Denominator:
Weighted average common shares and common share equivalents outstanding — basic372.2 372.7 372.6 371.8 
Effect of dilutive common share equivalents:
Nonvested restricted shares1.6 1.8 1.7 1.9 
Stock options (1)6.1 7.1 6.5 7.2 
Weighted average common shares and common share equivalents outstanding — diluted379.9 381.6 380.8 380.9 
Earnings per common share:
Basic$3.30 $3.38 $4.81 $6.37 
Diluted$3.23 $3.30 $4.70 $6.22 
(1)    Certain stock options were not included in the computation of diluted earnings per share where the exercise price of the stock options exceeded the average market price and would have been anti-dilutive or where, when applying the treasury stock method to in-the-money options, the sum of the proceeds, including unrecognized compensation, exceeded the average market price and would have been anti-dilutive. For the 2025 second quarter and 2024 second quarter, the number of stock options excluded were 2.2 million and 0.2 million, respectively. For the six months ended June 30, 2025 and 2024, the number of stock options excluded were 2.4 million and 0.4 million, respectively.
v3.25.2
Segment Information (Tables)
 6 Months Ended
Jun. 30, 2025
Segment Reporting [Abstract]  
Analysis of underwriting income or loss by segment and reconciliation to net income available to common shareholders
The following tables summarize the Company’s underwriting income or loss by segment, together with a reconciliation of underwriting income or loss to net income available to Arch common shareholders:
Three Months Ended
June 30, 2025
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$2,681 $3,196 $323 $6,196 
Premiums ceded (1)(645)(1,137)(70)(1,848)
Net premiums written2,036 2,059 253 4,348 
Change in unearned premiums(67)28 28 (11)
Net premiums earned1,969 2,087 281 4,337 
Other underwriting income (2)13 46 3 62 
Losses and loss adjustment expenses(1,178)(1,128)3 (2,303)
Acquisition expenses(387)(436)(1)(824)
Other operating expenses (3)(288)(118)(48)(454)
Underwriting income (loss)$129 $451 $238 818 
Net investment income405 
Net realized gains (losses)229 
Equity in net income of investments accounted for using the equity method162 
Other income (loss)18 
Corporate expenses (4)(29)
Transaction costs and other (4)(18)
Amortization of intangible assets(48)
Interest expense(38)
Net foreign exchange gains (losses)(88)
Income (loss) before income taxes and income (loss) from operating affiliates1,411 
Income tax (expense) benefit(214)
Income (loss) from operating affiliates40 
Net income (loss) available to Arch1,237 
Preferred dividends(10)
Net income (loss) available to Arch common shareholders$1,227 
Underwriting Ratios
Loss ratio59.8 %54.1 %(1.2)%53.1 %
Acquisition expense ratio19.6 %20.9 %0.4 %19.0 %
Other operating expense ratio (5)14.0 %3.5 %16.0 %9.1 %
Combined ratio93.4 %78.5 %15.2 %81.2 %
Goodwill and intangible assets$875 $105 $339 $1,319 
(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other underwriting income’ includes revenue earned from underwriting-related activities covered under existing service contracts.
(3)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(4)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
(5)    The ‘Other operating expense ratio’ for the 2025 period includes ‘Other underwriting income.’
Three Months Ended
June 30, 2024
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$2,102 $2,941 $340 $5,382 
Premiums ceded (1)(544)(994)(64)(1,601)
Net premiums written1,558 1,947 276 3,781 
Change in unearned premiums(80)(167)31 (216)
Net premiums earned1,478 1,780 307 3,565 
Other underwriting income— 1 2 3 
Losses and loss adjustment expenses(848)(1,006)27 (1,827)
Acquisition expenses(288)(345)— (633)
Other operating expenses (2)(233)(64)(49)(346)
Underwriting income (loss)$109 $366 $287 762 
Net investment income364 
Net realized gains (losses)122 
Equity in net income of investments accounted for using the equity method167 
Other income (loss)8 
Corporate expenses (3)(23)
Transaction costs and other (3)(18)
Amortization of intangible assets(27)
Interest expense(35)
Net foreign exchange gains (losses)1 
Income (loss) before income taxes and income (loss) from operating affiliates1,321 
Income tax (expense) benefit(97)
Income (loss) from operating affiliates45 
Net income (loss) available to Arch1,269 
Preferred dividends(10)
Net income (loss) available to Arch common shareholders$1,259 
Underwriting Ratios    
Loss ratio57.3 %56.5 %(8.6)%51.2 %
Acquisition expense ratio19.5 %19.4 %0.1 %17.8 %
Other operating expense ratio15.8 %3.6 %15.9 %9.7 %
Combined ratio92.6 %79.5 %7.4 %78.7 %
Goodwill and intangible assets$255 $114 $356 $725 

(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(3)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
Six Months Ended
June 30, 2025
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$5,326 $6,690 $649 $12,659 
Premiums ceded (1)(1,357)(2,315)(130)(3,796)
Net premiums written3,969 4,375 519 8,863 
Change in unearned premiums(140)(260)62 (338)
Net premiums earned3,829 4,115 581 8,525 
Other underwriting income (2)16 85 14 115 
Losses and loss adjustment expenses(2,406)(2,484)— (4,890)
Acquisition expenses(730)(853)(5)(1,588)
Other operating expenses (3)(582)(245)(100)(927)
Underwriting income (loss)$127 $618 $490 1,235 
Net investment income783 
Net realized gains (losses)232 
Equity in net income of investments accounted for using the equity method215 
Other income (loss)16 
Corporate expenses (4)(79)
Transaction costs and other (4)(28)
Amortization of intangible assets(97)
Interest expense(73)
Net foreign exchange gains (losses)(115)
Income (loss) before income taxes and income (loss) from operating affiliates2,089 
Income tax (expense) benefit(335)
Income (loss) from operating affiliates57 
Net income (loss) available to Arch1,811 
Preferred dividends(20)
Net income (loss) available to Arch common shareholders$1,791 
Underwriting Ratios
Loss ratio62.8 %60.4 %— %57.4 %
Acquisition expense ratio19.1 %20.7 %0.9 %18.6 %
Other operating expense ratio (5)14.8 %3.9 %14.9 %9.5 %
Combined ratio96.7 %85.0 %15.8 %85.5 %
(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other underwriting income’ includes revenue earned from underwriting-related activities covered under existing service contracts.
(3)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(4)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
(5)    The ‘Other operating expense ratio’ for the 2025 period includes ‘Other underwriting income.’
Six Months Ended
June 30, 2024
 InsuranceReinsuranceMortgageTotal
Gross premiums written (1)$4,228 $6,408 $681 $11,315 
Premiums ceded (1)(1,128)(2,195)(128)(3,449)
Net premiums written3,100 4,213 553 7,866 
Change in unearned premiums(171)(767)59 (879)
Net premiums earned2,929 3,446 612 6,987 
Other underwriting income— 3 12 15 
Losses and loss adjustment expenses(1,702)(1,889)36 (3,555)
Acquisition expenses(564)(676)— (1,240)
Other operating expenses (2)(468)(139)(102)(709)
Underwriting income (loss)$195 $745 $558 1,498 
Net investment income691 
Net realized gains (losses)189 
Equity in net income of investments accounted for using the equity method266 
Other income (loss)22 
Corporate expenses (3)(69)
Transaction costs and other (3)(25)
Amortization of intangible assets(48)
Interest expense(69)
Net foreign exchange gains (losses)32 
Income (loss) before income taxes and income (loss) from operating affiliates2,487 
Income tax (expense) benefit(198)
Income (loss) from operating affiliates100 
Net income (loss) available to Arch2,389 
Preferred dividends(20)
Net income (loss) available to Arch common shareholders$2,369 
Underwriting Ratios
Loss ratio58.1 %54.8 %(5.8)%50.9 %
Acquisition expense ratio19.2 %19.6 %0.1 %17.7 %
Other operating expense ratio16.0 %4.0 %16.7 %10.1 %
Combined ratio93.3 %78.4 %11.0 %78.7 %
(1)    Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
(2)    ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
(3)    Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
v3.25.2
Reserve for Losses and Loss Adjustment Expenses (Tables)
 6 Months Ended
Jun. 30, 2025
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]  
Analysis of losses and loss adjustment expenses and reconciliation of beginning and ending reserve balances
The following table represents an analysis of losses and loss adjustment expenses and a reconciliation of the beginning and ending reserve for losses and loss adjustment expenses:
Three Months EndedSix Months Ended
June 30,June 30,
2025202420252024
Reserve for losses and loss adjustment expenses at beginning of period
$30,946 $23,705 $29,369 $22,752 
Unpaid losses and loss adjustment expenses recoverable
8,379 7,069 7,821 6,690 
Net reserve for losses and loss adjustment expenses at beginning of period
22,567 16,636 21,548 16,062 
Net incurred losses and loss adjustment expenses relating to losses occurring in:
Current year
2,456 1,948 5,240 3,800 
Prior years
(153)(121)(350)(245)
Total net incurred losses and loss adjustment expenses
2,303 1,827 4,890 3,555 
Net losses and loss adjustment expense reserves of acquired businesses (1) 50 50 50 50 
Net foreign exchange (gains) losses and other
400 (10)593 (94)
Net paid losses and loss adjustment expenses relating to losses occurring in:
Current year
(424)(193)(865)(285)
Prior years
(1,320)(927)(2,640)(1,905)
Total net paid losses and loss adjustment expenses
(1,744)(1,120)(3,505)(2,190)
Net reserve for losses and loss adjustment expenses at end of period
23,576 17,383 23,576 17,383 
Unpaid losses and loss adjustment expenses recoverable
8,513 7,083 8,513 7,083 
Reserve for losses and loss adjustment expenses at end of period
$32,089 $24,466 $32,089 $24,466 
(1)     Activity in the 2025 periods related to the MCE Acquisition (see note 2). Activity in the 2024 periods related to the acquisition of RMIC Companies, Inc. and its wholly-owned subsidiaries that, together, comprise the run-off mortgage insurance business of Old Republic International Corporation.
Summary of (favorable) adverse net PYD by segment and tail length The table below summarizes (favorable) and adverse net PYD by segment and tail length:
Three Months EndedSix Months Ended
(Favorable) AdverseJune 30,June 30,
2025Short-tailedLong-tailedTotalShort-tailedLong-tailedTotal
Insurance$(13)$5 $(8)$(28)$3 $(25)
Reinsurance(75)(6)(81)(202)2 (200)
Mortgage(64)— (64)(125)— (125)
Total$(152)$(1)$(153)$(355)$5 $(350)
2024
Insurance$(13)$8 $(5)$(30)$15 $(15)
Reinsurance(48)14 (34)(91)17 (74)
Mortgage(82)— (82)(156)— (156)
Total$(143)$22 $(121)$(277)$32 $(245)
v3.25.2
Allowance for Expected Credit Losses (Tables)
 6 Months Ended
Jun. 30, 2025
Credit Loss [Abstract]  
Premiums receivable
The following table provides a roll forward of the allowance for expected credit losses of the Company’s premium receivables:
Premium Receivables, Net of AllowanceAllowance for Expected Credit Losses
Three Months Ended June 30, 2025
Balance at beginning of period$6,607 $43 
Change for provision of expected credit losses (1) 3 
Balance at end of period$7,067 $46 
Three Months Ended June 30, 2024
Balance at beginning of period$5,765 $32 
Change for provision of expected credit losses (1) 4 
Balance at end of period$6,268 $36 
Six Months Ended June 30, 2025
Balance at beginning of year$5,634 $45 
Change for provision of expected credit losses (1) 1 
Balance at end of period$7,067 $46 
Six Months Ended June 30, 2024
Balance at beginning of year$4,644 $34 
Change for provision of expected credit losses (1)
2 
Balance at end of period$6,268 $36 

(1)    Amounts deemed uncollectible are written-off in operating expenses. For the 2025 second quarter and 2024 second quarter, amounts written off were $1 million and nil, respectively. For the six months ended June 30, 2025 and 2024 period, amounts written off were $1 million and nil, respectively.
Reinsurance recoverables
The following table provides a roll forward of the allowance for expected credit losses of the Company’s reinsurance recoverables:
Reinsurance Recoverables, Net of AllowanceAllowance for Expected Credit Losses
Three Months Ended June 30, 2025
Balance at beginning of period$8,969 $17 
Change for provision of expected credit losses2 
Balance at end of period$9,044 $19 
Three Months Ended June 30, 2024
Balance at beginning of period$7,509 $16 
Change for provision of expected credit losses4 
Balance at end of period$7,473 $20 
Six Months Ended June 30, 2025
Balance at beginning of year$8,260 $17 
Change for provision of expected credit losses2 
Balance at end of period$9,044 $19 
Six Months Ended June 30, 2024
Balance at beginning of year$7,064 $21 
Change for provision of expected credit losses(1)
Balance at end of period$7,473 $20 
Ceded credit risk
The following table summarizes the Company’s reinsurance recoverables on paid and unpaid losses (not including ceded unearned premiums):
June 30,
December 31,
20252024
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses$9,044$8,260
% due from carriers with A.M. Best rating of “A-” or better62.5 %63.8 %
% due from all other carriers with no A.M. Best rating (1)37.5 %36.2 %
Largest balance due from any one carrier as % of total shareholders’ equity7.9 %7.8 %
(1)    At June 30, 2025 and December 31, 2024 over 95% of such amount were collateralized through reinsurance trusts, funds withheld arrangements, letters of credit or other.
Contractholder receivables
The following table provides a roll forward of the allowance for expected credit losses of the Company’s contractholder receivables:
Contract-holder Receivables, Net of AllowanceAllowance for Expected Credit Losses
Three Months Ended June 30, 2025
Balance at beginning of period$2,212 $6 
Change for provision of expected credit losses— 
Balance at end of period$2,280 $6 
Three Months Ended June 30, 2024
Balance at beginning of period$1,907 $3 
Change for provision of expected credit losses1 
Balance at end of period2,016 $4 
Six Months Ended June 30, 2025
Balance at beginning of year$2,161 $5 
Change for provision of expected credit losses1 
Balance at end of period$2,280 $6 
Six Months Ended June 30, 2024
Balance at beginning of year$1,814 $3 
Change for provision of expected credit losses1 
Balance at end of period2,016 $4 
v3.25.2
Investment Information (Tables)
 6 Months Ended
Jun. 30, 2025
Disclosure Investment Information [Abstract]  
Summary of fair value and cost or amortized cost of available for sale securities
The following table summarizes the fair value and cost or amortized cost of the Company’s securities classified as available for sale:
Estimated
Fair
Value		Gross
Unrealized
Gains		Gross
Unrealized
Losses		Allowance for Expected Credit Losses Cost or
Amortized
Cost
June 30, 2025
Fixed maturities:
Corporate bonds$14,429 $273 $(218)$(16)$14,390 
U.S. government and government agencies6,585 38 (48)— 6,595 
Asset backed securities2,770 18 (20)(10)2,782 
Non-U.S. government securities3,149 82 (70)(2)3,139 
Commercial mortgage backed securities838 7 (7)— 838 
Residential mortgage backed securities2,386 24 (24)— 2,386 
Municipal bonds175 — (7)— 182 
Total30,332 442 (394)(28)30,312 
Short-term investments2,788 3 (1)— 2,786 
Total$33,120 $445 $(395)$(28)$33,098 
December 31, 2024
Fixed maturities:
Corporate bonds$12,487 $110 $(346)$(12)$12,735 
U.S. government and government agencies6,710 8 (149)— 6,851 
Asset backed securities2,900 19 (32)(8)2,921 
Non-U.S. government securities2,538 30 (107)(1)2,616 
Commercial mortgage backed securities1,058 6 (11)(1)1,064 
Residential mortgage backed securities1,079 6 (31)— 1,104 
Municipal bonds263 — (16)— 279 
Total27,035 179 (692)(22)27,570 
Short-term investments2,784 2 (2)— 2,784 
Total$29,819 $181 $(694)$(22)$30,354 
Summary of available for sale securities in an unrealized loss position
The following table summarizes, for all available for sale securities in an unrealized loss position, the fair value and gross unrealized loss by length of time the security has been in a continual unrealized loss position:
 Less than 12 Months12 Months or MoreTotal
Estimated
Fair
Value		Gross
Unrealized
Losses		Estimated
Fair
Value		Gross
Unrealized
Losses		Estimated
Fair
Value		Gross
Unrealized
Losses
June 30, 2025
Fixed maturities:
Corporate bonds$1,944 $(83)$2,043 $(135)$3,987 $(218)
U.S. government and government agencies1,727 (29)308 (19)2,035 (48)
Non-U.S. government securities1,132 (25)395 (45)1,527 (70)
Residential mortgage backed securities158 (3)175 (21)333 (24)
Asset backed securities497 (4)348 (16)845 (20)
Commercial mortgage backed securities276 (2)188 (5)464 (7)
Municipal bonds15 — 147 (7)162 (7)
Total5,749 (146)3,604 (248)9,353 (394)
Short-term investments394 (1)— — 394 (1)
Total$6,143 $(147)$3,604 $(248)$9,747 $(395)
December 31, 2024
Fixed maturities:
Corporate bonds$4,582 $(114)$2,924 $(232)$7,506 $(346)
U.S. government and government agencies5,130 (100)516 (49)5,646 (149)
Non-U.S. government securities1,650 (58)418 (49)2,068 (107)
Residential mortgage backed securities571 (6)186 (25)757 (31)
Asset backed securities236 (8)426 (24)662 (32)
Commercial mortgage backed securities180 (1)434 (10)614 (11)
Municipal bonds48 (1)176 (15)224 (16)
Total12,397 (288)5,080 (404)17,477 (692)
Short-term investments97 (2)— — 97 (2)
Total$12,494 $(290)$5,080 $(404)$17,574 $(694)
Contractual maturities of the Company's fixed maturities
The contractual maturities of the Company’s fixed maturities are shown in the following table. Expected maturities, which are management’s best estimates, will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
June 30, 2025December 31, 2024
MaturityEstimated
Fair
Value		Amortized
Cost		Estimated
Fair
Value		Amortized
Cost
Due in one year or less$480 $490 $438 $451 
Due after one year through five years17,031 16,947 15,364 15,590 
Due after five years through 10 years6,123 6,168 5,811 6,039 
Due after 10 years704 701 385 401 
 24,338 24,306 21,998 22,481 
Residential mortgage backed securities2,386 2,386 1,079 1,104 
Commercial mortgage backed securities838 838 1,058 1,064 
Asset backed securities2,770 2,782 2,900 2,921 
Total$30,332 $30,312 $27,035 $27,570 
Summary of other investments, at fair value
The following table summarizes the Company’s other investments:
June 30,
2025		December 31,
2024
Other investments$1,810 $2,135 
Fixed maturities 1,009 854 
Short term investments68 70 
Equity securities5 7 
Total$2,892 $3,066 
The following table summarizes the Company’s other investments, as detailed in the previous table, by strategy:
June 30,
2025		December 31,
2024
Investment grade fixed income$1,029 $1,055 
Private equity252 229 
Lending238 303 
Term loan investments217 430 
Credit related funds72 99 
Energy2 19 
Total$1,810 $2,135 
Components of net investment income
The components of net investment income were derived from the following sources:
June 30,
 20252024
Three Months Ended
Fixed maturities$360 $306 
Short term investments24 35 
Equity securities10 10 
Other (1)35 35 
Gross investment income429 386 
Investment expenses(24)(22)
Net investment income$405 $364 
Six Months Ended
Fixed maturities$702 $586 
Short term investments50 64 
Equity securities21 18 
Other (1)63 68 
Gross investment income836 736 
Investment expenses(53)(45)
Net investment income$783 $691 
(1)    Amounts include dividends and other distributions on investment funds, term loan investments, funds held balances, cash balances and other items.
Summary of net realized gains (losses), including change in allowance for credit losses on financial assets and net impairment losses recognized in earnings
Net realized gains (losses), which include changes in the allowance for credit losses on financial assets and net impairment losses recognized in earnings were as follows:
June 30,
 20252024
Three Months Ended
Available for sale securities:  
Gross gains on investment sales$69 $13 
Gross losses on investment sales(56)(77)
Change in fair value of assets and liabilities accounted for using the fair value option:
Fixed maturities20 (4)
Other investments(11)(28)
Short-term investments3 — 
Equity securities, at fair value:
Net realized gains (losses) on sales during the period7 5 
Net unrealized gains (losses) on equity securities still held at reporting date129 7 
Allowance for credit losses:
Investments related(8)4 
Underwriting related(2)(3)
Derivative instruments (1)163 1 
Other (2)(85)204 
Net realized gains (losses)$229 $122 
Six Months Ended
Available for sale securities:
Gross gains on investment sales$120 $63 
Gross losses on investment sales(169)(155)
Change in fair value of assets and liabilities accounted for using the fair value option:
Fixed maturities22 (2)
Other investments2 (30)
Short-term investments3 — 
Equity securities, at fair value:
Net realized gains (losses) on sales during the period54 16 
Net unrealized gains (losses) on equity securities still held at reporting date34 89 
Allowance for credit losses:
Investments related(8)(2)
Underwriting related(1)(2)
Derivative instruments (1)262 (9)
Other (2)(87)221 
Net realized gains (losses)$232 $189 
(1)    See note 10 for information on the Company’s derivative instruments.
(2)    Amounts in the 2025 periods primarily include losses related to the anticipated sale of certain alternative investments accounted for under the equity method.
Summary of investments accounted for using equity method
The following table summarizes the Company’s investments accounted for using the equity method, by strategy:
June 30,
2025		December 31,
2024
Private equity$2,101 $1,915 
Credit related funds1,637 1,487 
Lending850 616 
Real estate837 869 
Fixed income462 384 
Infrastructure417 425 
Equities215 217 
Energy47 67 
Total$6,566 $5,980 
Summary of investments in limited partnership interests where the Company has a variable interest
The following table summarizes investments in limited partnership interests where the Company has a variable interest by balance sheet line item:
June 30,
2025		December 31,
2024
Investments accounted for using the equity method (1)$6,566 $5,980 
Investments accounted for using the fair value option (2)32 48 
Total$6,598 $6,028 
(1)    Aggregate unfunded commitments were $4.2 billion at June 30, 2025, compared to $4.3 billion at December 31, 2024.
(2)    Aggregate unfunded commitments were $22 million at June 30, 2025, compared to $21 million at December 31, 2024.
Rollforward of the allowance for expected credit losses of securities classified as available for sale
The following table provides a roll forward of the allowance for expected credit losses of the Company’s securities classified as available for sale:
Structured Securities (1)Corporate
Bonds		Non-U.S.
Government
Securities		Total
Three Months Ended June 30, 2025
Balance at beginning of period$8 $12 $1 $21 
Additions for current-period provision for expected credit losses— 2 — 2 
Additions (reductions) for previously recognized expected credit losses 2 4 1 7 
Reductions due to disposals— (2)— (2)
Balance at end of period$10 $16 $2 $28 
Three Months Ended June 30, 2024
Balance at beginning of period$7 $24 $1 $32 
Additions for current-period provision for expected credit losses— — — — 
Additions (reductions) for previously recognized expected credit losses 3 (6)— (3)
Reductions due to disposals— (2)— (2)
Balance at end of period$10 $16 $1 $27 
Six Months Ended June 30, 2025
Balance at beginning of year$9 $12 $1 $22 
Additions for current-period provision for expected credit losses3 2 — 5 
Additions (reductions) for previously recognized expected credit losses(2)5 1 4 
Reductions due to disposals— (3)— (3)
Balance at end of period$10 $16 $2 $28 
Six Months Ended June 30, 2024
Balance at beginning of year$7 $20 $1 $28 
Additions for current-period provision for expected credit losses— — — — 
Additions (reductions) for previously recognized expected credit losses3 (1)— 2 
Reductions due to disposals— (3)— (3)
Balance at end of period$10 $16 $1 $27 
(1)    Includes asset backed securities, residential mortgage backed securities and commercial mortgage backed securities.
Summary of restricted assets
The following table details the value of the Company’s restricted assets:
June 30,
2025		December 31,
2024
Assets used for collateral or guarantees:  
Affiliated transactions$5,229 $4,730 
Third party agreements6,512 5,999 
Deposits with U.S. regulatory authorities955 882 
Other (1)1,515 1,437 
Total restricted assets$14,211 $13,048 
(1)    Primarily includes Funds at Lloyds, deposits with non-U.S. regulatory authorities and other restricted assets.
Reconciliation of cash and restricted cash
The following table details reconciliation of cash and restricted cash within the Consolidated Balance Sheets:
June 30,
2025		December 31,
2024
Cash$983 $979 
Restricted cash (included in ‘other assets’)825 781 
Cash and restricted cash$1,808 $1,760 
v3.25.2
Fair Value (Tables)
 6 Months Ended
Jun. 30, 2025
Fair Value Disclosures [Abstract]  
Fair value hierarchy
The following table presents the Company’s financial assets and liabilities measured at fair value by level at June 30, 2025:
  Estimated Fair Value Measurements Using:
 Estimated
Fair
Value		Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)		Significant
Other
Observable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets measured at fair value:    
Available for sale securities:    
Fixed maturities:    
Corporate bonds$14,429 $— $14,284 $145 
U.S. government and government agencies6,585 6,585 — — 
Asset backed securities2,770 — 2,753 17 
Non-U.S. government securities3,149 — 3,149 — 
Commercial mortgage backed securities838 — 838 — 
Residential mortgage backed securities2,386 — 2,386 — 
Municipal bonds175 — 175 — 
Total30,332 6,585 23,585 162 
Short-term investments2,788 2,735 53 — 
Equity securities, at fair value1,715 1,680 27 8 
Derivative instruments (2)271 — 271 — 
Residential mortgage loans27 — 27 — 
Fair value option:
Corporate bonds988 — 988 — 
Non-U.S. government securities15 — 15 — 
U.S. government and government agencies6 6 — — 
Short-term investments68 6 17 45 
Equity securities5 — — 5 
Other investments423 — 215 208 
Other investments measured at net asset value (1)1,387 
Total2,892 12 1,235 258 
Total assets measured at fair value$38,025 $11,012 $25,198 $428 
Liabilities measured at fair value:    
Other liabilities$(20)$— $— $(20)
Derivative instruments (2)(159)— (159)— 
Total liabilities measured at fair value$(179)$— $(159)$(20)

(1)    In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
(2)    See note 10.
The following table presents the Company’s financial assets and liabilities measured at fair value by level at December 31, 2024:
  Estimated Fair Value Measurements Using:
 Estimated
Fair
Value		Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)		Significant
Other
Observable
Inputs
(Level 2)		Significant
Unobservable
Inputs
(Level 3)
Assets measured at fair value:
Available for sale securities:
Fixed maturities:
Corporate bonds$12,487 $— $12,390 $97 
U.S. government and government agencies6,710 6,709 1 — 
Asset backed securities2,900 — 2,900 — 
Non-U.S. government securities2,538 — 2,538 — 
Commercial mortgage backed securities1,058 — 1,058 — 
Residential mortgage backed securities1,079 — 1,079 — 
Municipal bonds263 — 263 — 
Total27,035 6,709 20,229 97 
Short-term investments2,784 2,704 80 — 
Equity securities, at fair value1,675 1,640 28 7 
Derivative instruments (2)206 — 206 — 
Residential mortgage loans15 — 15 — 
Fair value option:
Corporate bonds832 — 832 — 
Non-U.S. government securities8 — 8 — 
Asset backed securities— — — — 
U.S. government and government agencies14 14 — — 
Short-term investments70 — 37 33 
Equity securities6 2 — 4 
Other investments752 — 563 189 
Other investments measured at net asset value (1)1,383 
Total3,065 16 1,440 226 
Total assets measured at fair value$34,780 $11,069 $21,998 $330 
Liabilities measured at fair value:
Other liabilities$(73)$— $— $(73)
Derivative instruments (2)(115)— (115)— 
Total liabilities measured at fair value$(188)$— $(115)$(73)

(1)    In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
(2)    See note 10.
Rollforward of Level 3 investments
The following table presents a reconciliation of the beginning and ending balances for all financial assets and liabilities measured at fair value on a recurring basis using Level 3 inputs:
AssetsLiabilities
sAvailable For SaleFair Value OptionFair Value
 Structured Securities (1)Corporate
Bonds		Short-term
Investments		Other
Investments		Short-term
Investments		Equity
Securities		Equity
Securities		Other Liabilities
Three Months Ended June 30, 2025  
Balance at beginning of period$— $150 $— $206 $29 $4 $7 $(34)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — — — 1 — — 
Included in other comprehensive income— — — — — — — (2)
Purchases, issuances, sales and settlements
Purchases14 — — 44 18 — 1 — 
Issuances— — — — — — — — 
Sales— — — (3)— — — — 
Settlements(2)(5)— (39)(2)— — 16 
Transfers in and/or out of Level 35 — — — — — — — 
Balance at end of period$17 $145 $— $208 $45 $5 $8 $(20)
Three Months Ended June 30, 2024  
Balance at beginning of period$— $160 $97 $126 $17 $4 $5 $(22)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — — — — — — 
Included in other comprehensive income— — — — — — — — 
Purchases, issuances, sales and settlements
Purchases— — — 30 3 — 1 — 
Issuances— — — — — — — (13)
Sales — — — (2)— — — — 
Settlements— — — (10)(6)— — — 
Transfers in and/or out of Level 3— — — — — — — — 
Balance at end of period$— $160 $97 $144 $14 $4 $6 $(35)
Six Months Ended June 30, 2025  
Balance at beginning of year$— $97 $— $189 $33 $4 $7 $(73)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — — — 1 — 2 
Included in other comprehensive income— — — — — — — (2)
Purchases, issuances, sales and settlements
Purchases14 — — 96 24 — 1 — 
Issuances— — — — — — — — 
Sales — — — (3)— — — — 
Settlements(2)(22)— (74)(12)— — 53 
Transfers in and/or out of Level 35 70 — — — — — — 
Balance at end of period$17 $145 $— $208 $45 $5 $8 $(20)
Six Months Ended June 30, 2024  
Balance at beginning of year$— $147 $84 $106 $10 $4 $5 $(22)
Total gains or (losses) (realized/unrealized)
Included in earnings (2)— — — (4)— — — (1)
Included in other comprehensive income— 2 1 — — — — 1 
Purchases, issuances, sales and settlements
Purchases— 98 12 60 10 — 1 — 
Issuances— — — — — — — (13)
Sales— — — (2)— — — — 
Settlements— (87)— (16)(6)— — — 
Transfers in and/or out of Level 3— — — — — — — — 
Balance at end of period$— $160 $97 $144 $14 $4 $6 $(35)
(1)     Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities.
(2)     Gains or losses were included in net realized gains (losses).
v3.25.2
Derivative Instruments (Tables)
 6 Months Ended
Jun. 30, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Fair value and notional amount of derivatives
The following table summarizes information on the fair values and notional values of the Company’s derivative instruments:
 Estimated Fair Value
 Asset Derivatives (1)Liability Derivatives (1)Notional
Value (2)
June 30, 2025
Futures contracts$110 $(11)$8,208 
Foreign currency forward contracts92 (62)2,123 
Other (3)69 (86)2,073 
Total$271 $(159)
December 31, 2024
Futures contracts$78 $(46)$4,781 
Foreign currency forward contracts90 (48)1,698 
Other (3)38 (21)236 
Total$206 $(115)
(1)    The fair value of asset derivatives are included in ‘other assets’ and the fair value of liability derivatives are included in ‘other liabilities.’
(2)    Represents the absolute notional value of all outstanding contracts, consisting of long and short positions.
(3)    Includes swaps, options and other derivatives contracts.
Summary of net realized gains (losses) recorded in the consolidated statements of income
Realized and unrealized contract gains or losses on the Company’s derivative instruments are reflected in ‘net realized gains (losses)’ in the consolidated statements of income, as summarized in the following table:
Derivatives not designated asJune 30,
hedging instruments:20252024
Three Months Ended
Net realized gains (losses):
Futures contracts$93 $(3)
Foreign currency forward contracts53 2 
Other (1)17 2 
Total$163 $1 
Six Months Ended
Net realized gains (losses):
Futures contracts$139 $(17)
Foreign currency forward contracts83 1 
Other (1)40 7 
Total$262 $(9)
(1)    Includes realized gains or losses on swaps, options and other derivatives contracts.
v3.25.2
Variable Interest Entities (Tables)
 6 Months Ended
Jun. 30, 2025
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]  
Total assets and maximum exposure to loss associated with VIEs
The following table summarizes the total assets of the Bellemeade entities:
June 30,
2025		December 31, 2024
Bellemeade Entities
(Issue Date)		Total VIE AssetsCoverage Remaining from Reinsurers (1)Total VIE
Assets
2021-3 Ltd. (Sep-21)205 19 363 
2022-1 Ltd. (Jan-22)59 14 202 
2022-2 Ltd. (Sep-22)53 100 180 
2023-1 Ltd. (Oct-23)174 44 186 
2024-1 Ltd. (Aug-24)163 41 163 
Total $654 $218 $1,094 
(1)     Coverage from a separate panel of reinsurers remaining at June 30, 2025.
v3.25.2
Other Comprehensive Income (Loss) (Tables)
 6 Months Ended
Jun. 30, 2025
Comprehensive Income Note Disclosure [Abstract]  
Details about amounts reclassified from AOCI
The following tables present details about amounts reclassified from accumulated other comprehensive income and the tax effects allocated to each component of other comprehensive income (loss):
Amounts Reclassified from AOCI
Consolidated Statement of IncomeThree Months EndedSix Months Ended
Details AboutLine Item That IncludesJune 30,June 30,
AOCI ComponentsReclassification2025202420252024
Unrealized appreciation (decline) on available-for-sale investments
Net realized gains (losses)$14 $(64)$(49)$(92)
Provision for credit losses(8)4 (8)(2)
Total before tax6 (60)(57)(94)
Income tax (expense) benefit1 7 12 12 
Net of tax$7 $(53)$(45)$(82)
Schedule of comprehensive income (loss)
Before Tax AmountTax Expense (Benefit)Net of Tax Amount
Three Months Ended June 30, 2025
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$304 $1 $303 
Less reclassification of net realized gains (losses) included in net income6 (1)7 
Foreign currency translation adjustments62 (2)64 
Other comprehensive income (loss)$360 $— $360 
Three Months Ended June 30, 2024
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$(36)$(10)$(26)
Less reclassification of net realized gains (losses) included in net income(60)(7)(53)
Foreign currency translation adjustments(16)— (16)
Other comprehensive income (loss)$8 $(3)$11 
Six Months Ended June 30, 2025
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$549 $12 $537 
Less reclassification of net realized gains (losses) included in net income(57)(12)(45)
Foreign currency translation adjustments88 (2)90 
Other comprehensive income (loss)$694 $22 $672 
Six Months Ended June 30, 2024
Unrealized appreciation (decline) in value of investments:
Unrealized holding gains (losses) arising during period$(187)$(20)$(167)
Less reclassification of net realized gains (losses) included in net income(94)(12)(82)
Foreign currency translation adjustments(49)— (49)
Other comprehensive income (loss)$(142)$(8)$(134)
v3.25.2
Acquisitions - Summary of allocation of purchase price (Details) - US MidCorp and Entertainment - USD ($)
$ in Millions
 3 Months Ended
Aug. 01, 2024
Jun. 30, 2025
Purchase price    
Business acquisition, cash paid $ 450  
Assets Acquired    
Cash and investments, at fair value 2,332  
Premiums receivable, net of commissions 224  
Other assets acquired 175  
Total assets acquired 3,296  
Liabilities Acquired    
Reserves for losses and loss adjustment expenses 2,468  
Unearned premiums 636  
Other liabilities acquired 18  
Total liabilities acquired 3,122  
Net assets acquired 174  
Goodwill 276  
Deferred tax asset, goodwill and intangibles 565  
Net deferred tax asset, loss reserves and unearned premium 24  
Goodwill, measurement period adjustment   $ 10
Reserves For Losses And Loss Adjustment Expenses    
Liabilities Acquired    
Loss reserves, fair value adjustment 130  
Distribution relationships    
Assets Acquired    
Intangible assets $ 220  
Useful life 10 years  
Value of business acquired    
Assets Acquired    
Intangible assets $ 165  
Other intangible assets    
Assets Acquired    
Intangible assets [1] $ 180  
Minimum | Value of business acquired    
Assets Acquired    
Useful life 1 year  
Minimum | Other intangible assets    
Assets Acquired    
Useful life 5 years  
Maximum | Value of business acquired    
Assets Acquired    
Useful life 2 years  
Maximum | Other intangible assets    
Assets Acquired    
Useful life 7 years  
[1]     Includes $130 million related to the net fair value adjustment to reserves for loss and loss adjustment expenses on August 1, 2024.
v3.25.2
Share Transactions - Share repurchases (Details) - Authorized Share Repurchase Program - Common shares - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Class of Stock [Line Items]    
Cumulative number of shares acquired since inception of share repurchase program 437,900,000  
Aggregate purchase price of shares acquired since inception of share repurchase program $ 6,300.0  
Treasury stock, shares acquired (shares) 4,100,000 0
Aggregate cost of shares repurchased $ 359.7  
Remaining authorized repurchase amount $ 637.1  
v3.25.2
Earnings Per Common Share (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Numerator:        
Net income available to Arch $ 1,237 $ 1,269 $ 1,811 $ 2,389
Preferred dividends (10) (10) (20) (20)
Net income (loss) available to Arch common shareholders, basic 1,227 1,259 $ 1,791 $ 2,369
Net income (loss) available to Arch common shareholders, diluted $ 1,227 $ 1,259    
Denominator:        
Weighted average common shares outstanding — basic 372.2 372.7 372.6 371.8
Effect of dilutive common share equivalents:        
Nonvested restricted shares 1.6 1.8 1.7 1.9
Stock options [1] 6.1 7.1 6.5 7.2
Weighted average common shares and common share equivalents outstanding — diluted 379.9 381.6 380.8 380.9
Earnings per common share:        
Basic (per share) $ 3.30 $ 3.38 $ 4.81 $ 6.37
Diluted (per share) $ 3.23 $ 3.30 $ 4.70 $ 6.22
Stock options        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Antidilutive securities excluded from computation of earnings per common share (shares) 2.2 0.2 2.4 0.4
[1] Certain stock options were not included in the computation of diluted earnings per share where the exercise price of the stock options exceeded the average market price and would have been anti-dilutive or where, when applying the treasury stock method to in-the-money options, the sum of the proceeds, including unrecognized compensation, exceeded the average market price and would have been anti-dilutive. For the 2025 second quarter and 2024 second quarter, the number of stock options excluded were 2.2 million and 0.2 million, respectively. For the six months ended June 30, 2025 and 2024, the number of stock options excluded were 2.4 million and 0.4 million, respectively.
v3.25.2
Segment Information - Summary of underwriting income or loss by segment (Details)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
USD ($)
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
segment
Jun. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Segment Reporting Information [Line Items]          
Number of segments | segment     3    
Gross premiums written $ 6,196 $ 5,382 $ 12,659 $ 11,315  
Premiums ceded (1,848) (1,601) (3,796) (3,449)  
Net premiums written 4,348 3,781 8,863 7,866  
Change in unearned premiums (11) (216) (338) (879)  
Net premiums earned 4,337 3,565 8,525 6,987  
Other underwriting income 62 3 115 15  
Losses and loss adjustment expenses (2,303) (1,827) (4,890) (3,555)  
Acquisition expenses (824) (633) (1,588) (1,240)  
Other operating expenses (454) (346) (927) (709)  
Underwriting income (loss) 818 762 1,235 1,498  
Net investment income 405 364 783 691  
Net realized gains (losses) 229 122 232 189  
Equity in net income of investments accounted for using the equity method 162 167 215 266  
Other income (loss) 18 8 16 22  
Corporate expenses [1] (29) (23) (79) (69)  
Transaction costs and other [1] (18) (18) (28) (25)  
Amortization of intangible assets (48) (27) (97) (48)  
Interest expense (38) (35) (73) (69)  
Net foreign exchange gains (losses) (88) 1 (115) 32  
Income (loss) before income taxes and income (loss) from operating affiliates 1,411 1,321 2,089 2,487  
Income tax expense (benefit) (214) (97) (335) (198)  
Income (loss) from operating affiliates 40 45 57 100  
Net income available to Arch 1,237 1,269 1,811 2,389  
Preferred dividends (10) (10) (20) (20)  
Net income (loss) available to Arch common shareholders $ 1,227 $ 1,259 $ 1,791 $ 2,369  
Underwriting Ratios          
Loss ratio 53.10% 51.20% 57.40% 50.90%  
Acquisition expense ratio 19.00% 17.80% 18.60% 17.70%  
Other operating expense ratio [2] 9.10%   9.50%    
Other operating expense ratio   9.70%   10.10%  
Combined ratio 81.20% 78.70% 85.50% 78.70%  
Goodwill and intangible assets $ 1,319 $ 725 $ 1,319 $ 725 $ 1,351
Operating segments | Insurance          
Segment Reporting Information [Line Items]          
Gross premiums written [3] 2,681 2,102 5,326 4,228  
Premiums ceded [3] (645) (544) (1,357) (1,128)  
Net premiums written 2,036 1,558 3,969 3,100  
Change in unearned premiums (67) (80) (140) (171)  
Net premiums earned 1,969 1,478 3,829 2,929  
Other underwriting income 13 [4] 0 16 [4] 0  
Losses and loss adjustment expenses (1,178) (848) (2,406) (1,702)  
Acquisition expenses (387) (288) (730) (564)  
Other operating expenses [5] (288) (233) (582) (468)  
Underwriting income (loss) $ 129 $ 109 $ 127 $ 195  
Underwriting Ratios          
Loss ratio 59.80% 57.30% 62.80% 58.10%  
Acquisition expense ratio 19.60% 19.50% 19.10% 19.20%  
Other operating expense ratio [2] 14.00%   14.80%    
Other operating expense ratio   15.80%   16.00%  
Combined ratio 93.40% 92.60% 96.70% 93.30%  
Goodwill and intangible assets $ 875 $ 255 $ 875 $ 255  
Operating segments | Reinsurance          
Segment Reporting Information [Line Items]          
Gross premiums written [3] 3,196 2,941 6,690 6,408  
Premiums ceded [3] (1,137) (994) (2,315) (2,195)  
Net premiums written 2,059 1,947 4,375 4,213  
Change in unearned premiums 28 (167) (260) (767)  
Net premiums earned 2,087 1,780 4,115 3,446  
Other underwriting income 46 [4] 1 85 [4] 3  
Losses and loss adjustment expenses (1,128) (1,006) (2,484) (1,889)  
Acquisition expenses (436) (345) (853) (676)  
Other operating expenses [5] (118) (64) (245) (139)  
Underwriting income (loss) $ 451 $ 366 $ 618 $ 745  
Underwriting Ratios          
Loss ratio 54.10% 56.50% 60.40% 54.80%  
Acquisition expense ratio 20.90% 19.40% 20.70% 19.60%  
Other operating expense ratio [2] 3.50%   3.90%    
Other operating expense ratio   3.60%   4.00%  
Combined ratio 78.50% 79.50% 85.00% 78.40%  
Goodwill and intangible assets $ 105 $ 114 $ 105 $ 114  
Operating segments | Mortgage          
Segment Reporting Information [Line Items]          
Gross premiums written [3] 323 340 649 681  
Premiums ceded [3] (70) (64) (130) (128)  
Net premiums written 253 276 519 553  
Change in unearned premiums 28 31 62 59  
Net premiums earned 281 307 581 612  
Other underwriting income 3 [4] 2 14 [4] 12  
Losses and loss adjustment expenses 3 27 0 36  
Acquisition expenses (1) 0 (5) 0  
Other operating expenses [5] (48) (49) (100) (102)  
Underwriting income (loss) $ 238 $ 287 $ 490 $ 558  
Underwriting Ratios          
Loss ratio (1.20%) (8.60%) 0.00% (5.80%)  
Acquisition expense ratio 0.40% 0.10% 0.90% 0.10%  
Other operating expense ratio [2] 16.00%   14.90%    
Other operating expense ratio   15.90%   16.70%  
Combined ratio 15.20% 7.40% 15.80% 11.00%  
Goodwill and intangible assets $ 339 $ 356 $ 339 $ 356  
[1] Certain expenses have been excluded from ‘Corporate expenses’ and reflected in ‘Transaction costs and other.’
[2] The ‘Other operating expense ratio’ for the 2025 period includes ‘Other underwriting income.’
[3] Certain assumed and ceded amounts related to intersegment transactions are included in individual segment results. Accordingly, the sum of such transactions for each segment does not agree to the total due to eliminations.
[4] ‘Other underwriting income’ includes revenue earned from underwriting-related activities covered under existing service contracts.
[5] ‘Other operating expenses’ primarily include expenses that are related to compensation and employee benefits, information technology and professional fees.
v3.25.2
Reserve for Losses and Loss Adjustment Expenses - Reconciliation of beginning and ending balances of losses and loss adjustment reserves (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]        
Reserve for losses and loss adjustment expenses at beginning of period $ 30,946 $ 23,705 $ 29,369 $ 22,752
Unpaid losses and loss adjustment expenses recoverable 8,379 7,069 7,821 6,690
Net reserve for losses and loss adjustment expenses at beginning of period 22,567 16,636 21,548 16,062
Net incurred losses and loss adjustment expenses relating to losses occurring in:        
Current year 2,456 1,948 5,240 3,800
Prior years (153) (121) (350) (245)
Total net incurred losses and loss adjustment expenses 2,303 1,827 4,890 3,555
Net losses and loss adjustment expense reserves of acquired business [1] 50 50 50 50
Net foreign exchange (gains) losses and other 400 (10) 593 (94)
Net paid losses and loss adjustment expenses relating to losses occurring in:        
Current year (424) (193) (865) (285)
Prior years (1,320) (927) (2,640) (1,905)
Total net paid losses and loss adjustment expenses (1,744) (1,120) (3,505) (2,190)
Net reserve for losses and loss adjustment expenses at end of period 23,576 17,383 23,576 17,383
Unpaid losses and loss adjustment expenses recoverable 8,513 7,083 8,513 7,083
Reserve for losses and loss adjustment expenses at end of period $ 32,089 $ 24,466 $ 32,089 $ 24,466
[1] Activity in the 2025 periods related to the MCE Acquisition (see note 2). Activity in the 2024 periods related to the acquisition of RMIC Companies, Inc. and its wholly-owned subsidiaries that, together, comprise the run-off mortgage insurance business of Old Republic International Corporation.
v3.25.2
Reserve for Losses and Loss Adjustment Expenses - Prior year development (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse $ (153) $ (121) $ (350) $ (245)
Operating segments        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (153) (121) (350) (245)
Operating segments | Short tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (152) (143) (355) (277)
Operating segments | Long tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (1) 22 5 32
Operating segments | Insurance        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (8) (5) (25) (15)
Operating segments | Insurance | Short tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (13) (13) (28) (30)
Operating segments | Insurance | Short tailed lines | Travel and accident        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (7)   (15)  
Operating segments | Insurance | Short tailed lines | Property, energy, marine and aviation        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse   15 (11)  
Operating segments | Insurance | Short tailed lines | Surety Product Line        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse   (20)   (25)
Operating segments | Insurance | Long tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse 5 8 3 15
Operating segments | Insurance | Long tailed lines | Programs business        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse 14 9   17
Operating segments | Reinsurance        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (81) (34) (200) (74)
Operating segments | Reinsurance | Short tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (75) (48) (202) (91)
Operating segments | Reinsurance | Short tailed lines | Property catastrophe        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse     (86)  
Operating segments | Reinsurance | Short tailed lines | Other specialty lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse       (37)
Operating segments | Reinsurance | Short tailed lines | Property other than property catastrophe        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (60) (30) (89) (51)
Operating segments | Reinsurance | Long tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (6) 14 2 17
Operating segments | Reinsurance | Long tailed lines | Casualty        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse   14   17
Operating segments | Mortgage        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (64) (82) (125) (156)
Operating segments | Mortgage | Short tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse (64) (82) (125) (156)
Operating segments | Mortgage | Long tailed lines        
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]        
Prior year development (favorable) adverse $ 0 $ 0 $ 0 $ 0
v3.25.2
Allowance for Expected Credit Losses - Premiums receivable (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Credit Loss [Abstract]        
Balance at beginning of period $ 6,607 $ 5,765 $ 5,634 $ 4,644
Balance at end of period 7,067 6,268 7,067 6,268
Allowance for Expected Credit Losses        
Balance at beginning of period 43 32 45 34
Change for provision of expected credit losses [1] 3 4 1 2
Balance at end of period 46 36 46 36
Premium receivable, write-offs during the period $ 1 $ 0 $ 1 $ 0
[1] Amounts deemed uncollectible are written-off in operating expenses. For the 2025 second quarter and 2024 second quarter, amounts written off were $1 million and nil, respectively. For the six months ended June 30, 2025 and 2024 period, amounts written off were $1 million and nil, respectively
v3.25.2
Allowance for Expected Credit Losses - Reinsurance recoverables (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Credit Loss [Abstract]        
Balance at beginning of period $ 8,969 $ 7,509 $ 8,260 $ 7,064
Balance at end of period 9,044 7,473 9,044 7,473
Allowance for Expected Credit Losses        
Balance at beginning of period 17 16 17 21
Change for provision of expected credit losses 2 4 2 (1)
Balance at end of period $ 19 $ 20 $ 19 $ 20
v3.25.2
Allowance for Expected Credit Losses - Ceded credit risk (Details) - USD ($)
$ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2025
Dec. 31, 2024
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2023
Ceded Credit Risk [Line Items]            
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses $ 9,044 $ 8,260 $ 8,969 $ 7,473 $ 7,509 $ 7,064
Reinsurance recoverable | Reinsurer concentration risk | AM Best A minus Or Better Rating            
Ceded Credit Risk [Line Items]            
Concentration risk percentage 62.50% 63.80%        
Reinsurance recoverable | Reinsurer concentration risk | Not Rated | All Other Carriers            
Ceded Credit Risk [Line Items]            
Concentration risk percentage [1] 37.50% 36.20%        
Reinsurance recoverable | Reinsurer concentration risk | Not Rated | Ceded credit risk, secured            
Ceded Credit Risk [Line Items]            
Concentration risk percentage 95.00% 95.00%        
Stockholders' equity | Reinsurer concentration risk | Largest Balance Due From Any One Carrier            
Ceded Credit Risk [Line Items]            
Concentration risk percentage 7.90% 7.80%        
[1] At June 30, 2025 and December 31, 2024 over 95% of such amount were collateralized through reinsurance trusts, funds withheld arrangements, letters of credit or other
v3.25.2
Allowance for Expected Credit Losses - Contractholder receivables (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Credit Loss [Abstract]        
Balance at beginning of period $ 2,212 $ 1,907 $ 2,161 $ 1,814
Balance at end of period 2,280 2,016 2,280 2,016
Allowance for Expected Credit Losses        
Balance at beginning of period 6 3 5 3
Change for provision of expected credit losses 0 1 1 1
Balance at end of period $ 6 $ 4 $ 6 $ 4
v3.25.2
Investment Information - Summary of available for sale securities (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value $ 33,120   $ 29,819      
Gross Unrealized Gains 445   181      
Gross Unrealized Losses (395)   (694)      
Allowance for Expected Credit Losses (28)   (22)      
Cost or Amortized Cost 33,098   30,354      
Fixed maturities            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 30,332   27,035      
Gross Unrealized Gains 442   179      
Gross Unrealized Losses (394)   (692)      
Allowance for Expected Credit Losses (28) $ (21) (22) $ (27) $ (32) $ (28)
Cost or Amortized Cost 30,312   27,570      
Corporate bonds            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 14,429   12,487      
Gross Unrealized Gains 273   110      
Gross Unrealized Losses (218)   (346)      
Allowance for Expected Credit Losses (16) (12) (12) (16) (24) (20)
Cost or Amortized Cost 14,390   12,735      
U.S. government and government agencies            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 6,585   6,710      
Gross Unrealized Gains 38   8      
Gross Unrealized Losses (48)   (149)      
Allowance for Expected Credit Losses 0   0      
Cost or Amortized Cost 6,595   6,851      
Asset backed securities            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 2,770   2,900      
Gross Unrealized Gains 18   19      
Gross Unrealized Losses (20)   (32)      
Allowance for Expected Credit Losses (10)   (8)      
Cost or Amortized Cost 2,782   2,921      
Non-U.S. government securities            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 3,149   2,538      
Gross Unrealized Gains 82   30      
Gross Unrealized Losses (70)   (107)      
Allowance for Expected Credit Losses (2) $ (1) (1) $ (1) $ (1) $ (1)
Cost or Amortized Cost 3,139   2,616      
Commercial mortgage backed securities            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 838   1,058      
Gross Unrealized Gains 7   6      
Gross Unrealized Losses (7)   (11)      
Allowance for Expected Credit Losses 0   (1)      
Cost or Amortized Cost 838   1,064      
Residential mortgage backed securities            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 2,386   1,079      
Gross Unrealized Gains 24   6      
Gross Unrealized Losses (24)   (31)      
Allowance for Expected Credit Losses 0   0      
Cost or Amortized Cost 2,386   1,104      
Municipal bonds            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 175   263      
Gross Unrealized Gains 0   0      
Gross Unrealized Losses (7)   (16)      
Allowance for Expected Credit Losses 0   0      
Cost or Amortized Cost 182   279      
Short-term investments            
Debt Securities, Available-for-sale [Line Items]            
Estimated Fair Value 2,788   2,784      
Gross Unrealized Gains 3   2      
Gross Unrealized Losses (1)   (2)      
Allowance for Expected Credit Losses 0   0      
Cost or Amortized Cost $ 2,786   $ 2,784      
v3.25.2
Investment Information - Aging of available for sale securities in an unrealized loss position (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months $ 6,143 $ 12,494
Estimated Fair Value - 12 Months or More 3,604 5,080
Estimated Fair Value 9,747 17,574
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (147) (290)
Gross Unrealized Losses - 12 Months or More (248) (404)
Gross Unrealized Losses (395) (694)
Fixed maturities    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 5,749 12,397
Estimated Fair Value - 12 Months or More 3,604 5,080
Estimated Fair Value 9,353 17,477
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (146) (288)
Gross Unrealized Losses - 12 Months or More (248) (404)
Gross Unrealized Losses (394) (692)
Corporate bonds    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 1,944 4,582
Estimated Fair Value - 12 Months or More 2,043 2,924
Estimated Fair Value 3,987 7,506
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (83) (114)
Gross Unrealized Losses - 12 Months or More (135) (232)
Gross Unrealized Losses (218) (346)
U.S. government and government agencies    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 1,727 5,130
Estimated Fair Value - 12 Months or More 308 516
Estimated Fair Value 2,035 5,646
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (29) (100)
Gross Unrealized Losses - 12 Months or More (19) (49)
Gross Unrealized Losses (48) (149)
Non-U.S. government securities    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 1,132 1,650
Estimated Fair Value - 12 Months or More 395 418
Estimated Fair Value 1,527 2,068
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (25) (58)
Gross Unrealized Losses - 12 Months or More (45) (49)
Gross Unrealized Losses (70) (107)
Residential mortgage backed securities    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 158 571
Estimated Fair Value - 12 Months or More 175 186
Estimated Fair Value 333 757
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (3) (6)
Gross Unrealized Losses - 12 Months or More (21) (25)
Gross Unrealized Losses (24) (31)
Asset backed securities    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 497 236
Estimated Fair Value - 12 Months or More 348 426
Estimated Fair Value 845 662
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (4) (8)
Gross Unrealized Losses - 12 Months or More (16) (24)
Gross Unrealized Losses (20) (32)
Commercial mortgage backed securities    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 276 180
Estimated Fair Value - 12 Months or More 188 434
Estimated Fair Value 464 614
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (2) (1)
Gross Unrealized Losses - 12 Months or More (5) (10)
Gross Unrealized Losses (7) (11)
Municipal bonds    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 15 48
Estimated Fair Value - 12 Months or More 147 176
Estimated Fair Value 162 224
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months 0 (1)
Gross Unrealized Losses - 12 Months or More (7) (15)
Gross Unrealized Losses (7) (16)
Short-term investments    
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value [Abstract]    
Estimated Fair Value - Less than 12 Months 394 97
Estimated Fair Value - 12 Months or More 0 0
Estimated Fair Value 394 97
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss [Abstract]    
Gross Unrealized Losses - Less than 12 Months (1) (2)
Gross Unrealized Losses - 12 Months or More 0 0
Gross Unrealized Losses $ (1) $ (2)
v3.25.2
Investment Information - Maturity profile of available for sale securities) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Estimated Fair Value    
Due in one year or less $ 480 $ 438
Due after one year through five years 17,031 15,364
Due after five years through 10 years 6,123 5,811
Due after 10 years 704 385
Single maturity date 24,338 21,998
Estimated Fair Value 33,120 29,819
Amortized Cost    
Due in one year or less 490 451
Due after one year through five years 16,947 15,590
Due after five years through 10 years 6,168 6,039
Due after 10 years 701 401
Single maturity date 24,306 22,481
Cost or Amortized Cost 33,098 30,354
Fixed maturities    
Estimated Fair Value    
Estimated Fair Value 30,332 27,035
Amortized Cost    
Cost or Amortized Cost 30,312 27,570
Residential mortgage backed securities    
Estimated Fair Value    
Securities without single maturity date 2,386 1,079
Estimated Fair Value 2,386 1,079
Amortized Cost    
Securities without single maturity date 2,386 1,104
Cost or Amortized Cost 2,386 1,104
Commercial mortgage backed securities    
Estimated Fair Value    
Securities without single maturity date 838 1,058
Estimated Fair Value 838 1,058
Amortized Cost    
Securities without single maturity date 838 1,064
Cost or Amortized Cost 838 1,064
Asset backed securities    
Estimated Fair Value    
Securities without single maturity date 2,770 2,900
Estimated Fair Value 2,770 2,900
Amortized Cost    
Securities without single maturity date 2,782 2,921
Cost or Amortized Cost $ 2,782 $ 2,921
v3.25.2
Investment Information - Other investments, at fair value (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Schedule Of Other Investments [Line Items]    
Other investments, at fair value $ 2,892 $ 3,066
Other investments    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 1,810 2,135
Investment grade fixed income    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 1,029 1,055
Private equity    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 252 229
Lending    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 238 303
Term loan investments    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 217 430
Credit related funds    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 72 99
Energy    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 2 19
Fixed maturities    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 1,009 854
Short term investments    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value 68 70
Equity securities    
Schedule Of Other Investments [Line Items]    
Other investments, at fair value $ 5 $ 7
v3.25.2
Investment Information - Net investment income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Net investment income:        
Gross investment income $ 429 $ 386 $ 836 $ 736
Investment expenses (24) (22) (53) (45)
Net investment income 405 364 783 691
Fixed maturities        
Net investment income:        
Gross investment income 360 306 702 586
Short-term investments        
Net investment income:        
Gross investment income 24 35 50 64
Equity securities        
Net investment income:        
Gross investment income 10 10 21 18
Other        
Net investment income:        
Gross investment income [1] $ 35 $ 35 $ 63 $ 68
[1] Amounts include dividends and other distributions on investment funds, term loan investments, funds held balances, cash balances and other items.
v3.25.2
Investment Information - Net realized gains and losses (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Available for sale securities:        
Available for sale securities, gross gains on investment sales $ 69 $ 13 $ 120 $ 63
Available for sale securities, gross losses on investment sales (56) (77) (169) (155)
Equity securities, at fair value:        
Net realized gains (losses) on sales during the period 7 5 54 16
Net unrealized gains (losses) on equity securities still held at reporting date 129 7 34 89
Allowance for credit losses:        
Allowance for credit losses - investments related (8) 4 (8) (2)
Allowance for credit losses - underwriting related (2) (3) (1) (2)
Derivative instruments [1] 163 1 262 (9)
Other (2) [2] (85) 204 (87) 221
Net realized gains (losses) 229 122 232 189
Fixed maturities        
Available for sale securities:        
Change in fair value of assets and liabilities accounted for using the fair value option 20 (4) 22 (2)
Other investments        
Available for sale securities:        
Change in fair value of assets and liabilities accounted for using the fair value option (11) (28) 2 (30)
Short term investments        
Available for sale securities:        
Change in fair value of assets and liabilities accounted for using the fair value option $ 3 $ 0 $ 3 $ 0
[1] See note 10 for information on the Company’s derivative instruments.
[2] Amounts in the 2025 periods primarily include losses related to the anticipated sale of certain alternative investments accounted for under the equity method.
v3.25.2
Investment Information - Investments accounted for using the equity method (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method $ 6,566 $ 5,980
Private equity    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 2,101 1,915
Credit related funds    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 1,637 1,487
Lending    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 850 616
Real estate    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 837 869
Fixed income    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 462 384
Infrastructure    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 417 425
Equity securities    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method 215 217
Energy    
Schedule of Equity Method Investments [Line Items]    
Investments accounted for using the equity method $ 47 $ 67
v3.25.2
Investment Information - Limited partnership interests (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]    
Maximum Exposure to Loss $ 6,598 $ 6,028
Aggregate unfunded commitments 4,300 4,400
Equity method investments    
Schedule of Equity Method Investments [Line Items]    
Maximum Exposure to Loss [1] 6,566 5,980
Aggregate unfunded commitments 4,200 4,300
Fair value option    
Schedule of Equity Method Investments [Line Items]    
Maximum Exposure to Loss [2] 32 48
Aggregate unfunded commitments $ 22 $ 21
[1] Aggregate unfunded commitments were $4.2 billion at June 30, 2025, compared to $4.3 billion at December 31, 2024.
[2] Aggregate unfunded commitments were $22 million at June 30, 2025, compared to $21 million at December 31, 2024
v3.25.2
Investment Information - Investment in operating affiliates (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]          
Investment in operating affiliates $ 1,356   $ 1,356   $ 1,240
Income (loss) from operating affiliates $ 40 $ 45 $ 57 $ 100  
Coface          
Schedule of Equity Method Investments [Line Items]          
Percentage ownership 29.90%   29.90%    
Investment in operating affiliates $ 654   $ 654   592
Greysbridge Holdings Ltd          
Schedule of Equity Method Investments [Line Items]          
Percentage ownership 40.00%   40.00%    
Investment in operating affiliates $ 582   $ 582   $ 523
Issued Shares Excluding Treasury Stock | Coface          
Schedule of Equity Method Investments [Line Items]          
Percentage ownership 30.00%   30.00%    
v3.25.2
Investment Information - Allowance for expected credit losses (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Allowance for expected credit losses        
Balance at beginning of period     $ 22  
Balance at end of period $ 28   28  
Fixed maturities        
Allowance for expected credit losses        
Balance at beginning of period 21 $ 32 22 $ 28
Additions for current-period provision for expected credit losses 2 0 5 0
Additions (reductions) for previously recognized expected credit losses 7 (3) 4 2
Reductions due to disposals (2) (2) (3) (3)
Balance at end of period 28 27 28 27
Structured securities        
Allowance for expected credit losses        
Balance at beginning of period [1] 8 7 9 7
Additions for current-period provision for expected credit losses [1] 0 0 3 0
Additions (reductions) for previously recognized expected credit losses [1] 2 3 (2) 3
Reductions due to disposals [1] 0 0 0 0
Balance at end of period [1] 10 10 10 10
Corporate bonds        
Allowance for expected credit losses        
Balance at beginning of period 12 24 12 20
Additions for current-period provision for expected credit losses 2 0 2 0
Additions (reductions) for previously recognized expected credit losses 4 (6) 5 (1)
Reductions due to disposals (2) (2) (3) (3)
Balance at end of period 16 16 16 16
Non-U.S. government securities        
Allowance for expected credit losses        
Balance at beginning of period 1 1 1 1
Additions for current-period provision for expected credit losses 0 0 0 0
Additions (reductions) for previously recognized expected credit losses 1 0 1 0
Reductions due to disposals 0 0 0 0
Balance at end of period $ 2 $ 1 $ 2 $ 1
[1] Includes asset backed securities, residential mortgage backed securities and commercial mortgage backed securities.
v3.25.2
Investment Information - Restricted assets (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Restricted Assets [Line Items]    
Restricted assets $ 14,211 $ 13,048
Collateral or guarantees - affiliated transactions    
Restricted Assets [Line Items]    
Restricted assets 5,229 4,730
Collateral or guarantees - third party agreements    
Restricted Assets [Line Items]    
Restricted assets 6,512 5,999
Deposits with US regulatory authorities    
Restricted Assets [Line Items]    
Restricted assets 955 882
Other    
Restricted Assets [Line Items]    
Restricted assets [1] $ 1,515 $ 1,437
[1] Primarily includes Funds at Lloyds, deposits with non-U.S. regulatory authorities and other restricted assets
v3.25.2
Investment Information - Cash and restricted cash (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Jun. 30, 2024
Dec. 31, 2023
Disclosure Investment Information [Abstract]        
Cash $ 983 $ 979    
Restricted cash (included in ‘other assets’) 825 781    
Cash and restricted cash $ 1,808 $ 1,760 $ 1,627 $ 1,498
v3.25.2
Investment Information - Narrative (Details)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
USD ($)
lots
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
lots
Jun. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
lots
Continuous unrealized loss, qualitative disclosures:          
Number of positions in an unrealized loss position (lots) | lots 6,560   6,560   9,980
Total number of positions (lots) | lots 23,600   23,600   20,930
Largest single loss $ 4   $ 4   $ 8
Narrative items:          
Equity securities, at fair value 1,715   1,715   $ 1,675
Equity in net (loss) income of investment funds accounted for using the equity method $ 162 $ 167 $ 215 $ 266  
Minimum          
Narrative items:          
Time lag for reporting     1 month    
Maximum          
Narrative items:          
Time lag for reporting     3 months    
v3.25.2
Fair Value - Fair Value Hierarchy (Details) - Recurring - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value $ 11,012 $ 11,069
Liabilities measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other liabilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential mortgage loans    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 6,585 6,709
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 6,585 6,709
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Commercial mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Residential mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed maturities | Municipal bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,735 2,704
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 1,680 1,640
Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 12 16
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 6 14
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value   0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Short term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 6 0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 2
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value option | Other investments fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 25,198 21,998
Liabilities measured at fair value (159) (115)
Significant Other Observable Inputs (Level 2) | Other liabilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value 0 0
Significant Other Observable Inputs (Level 2) | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value (159) (115)
Significant Other Observable Inputs (Level 2) | Residential mortgage loans    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 27 15
Significant Other Observable Inputs (Level 2) | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 23,585 20,229
Significant Other Observable Inputs (Level 2) | Fixed maturities | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 14,284 12,390
Significant Other Observable Inputs (Level 2) | Fixed maturities | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 1
Significant Other Observable Inputs (Level 2) | Fixed maturities | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,753 2,900
Significant Other Observable Inputs (Level 2) | Fixed maturities | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 3,149 2,538
Significant Other Observable Inputs (Level 2) | Fixed maturities | Commercial mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 838 1,058
Significant Other Observable Inputs (Level 2) | Fixed maturities | Residential mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,386 1,079
Significant Other Observable Inputs (Level 2) | Fixed maturities | Municipal bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 175 263
Significant Other Observable Inputs (Level 2) | Short-term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 53 80
Significant Other Observable Inputs (Level 2) | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 27 28
Significant Other Observable Inputs (Level 2) | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 271 206
Significant Other Observable Inputs (Level 2) | Fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 1,235 1,440
Significant Other Observable Inputs (Level 2) | Fair value option | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 988 832
Significant Other Observable Inputs (Level 2) | Fair value option | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Other Observable Inputs (Level 2) | Fair value option | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value   0
Significant Other Observable Inputs (Level 2) | Fair value option | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 15 8
Significant Other Observable Inputs (Level 2) | Fair value option | Short term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 17 37
Significant Other Observable Inputs (Level 2) | Fair value option | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Other Observable Inputs (Level 2) | Fair value option | Other investments fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 215 563
Significant Unobservable Inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 428 330
Liabilities measured at fair value (20) (73)
Significant Unobservable Inputs (Level 3) | Other liabilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value (20) (73)
Significant Unobservable Inputs (Level 3) | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Residential mortgage loans    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 162 97
Significant Unobservable Inputs (Level 3) | Fixed maturities | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 145 97
Significant Unobservable Inputs (Level 3) | Fixed maturities | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 17 0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Commercial mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Residential mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fixed maturities | Municipal bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Short-term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 8 7
Significant Unobservable Inputs (Level 3) | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 258 226
Significant Unobservable Inputs (Level 3) | Fair value option | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fair value option | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fair value option | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value   0
Significant Unobservable Inputs (Level 3) | Fair value option | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 0
Significant Unobservable Inputs (Level 3) | Fair value option | Short term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 45 33
Significant Unobservable Inputs (Level 3) | Fair value option | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 5 4
Significant Unobservable Inputs (Level 3) | Fair value option | Other investments fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 208 189
Estimated Fair Value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 38,025 34,780
Liabilities measured at fair value (179) (188)
Estimated Fair Value | Other liabilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value (20) (73)
Estimated Fair Value | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value (159) (115)
Estimated Fair Value | Residential mortgage loans    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 27 15
Estimated Fair Value | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 30,332 27,035
Estimated Fair Value | Fixed maturities | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 14,429 12,487
Estimated Fair Value | Fixed maturities | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 6,585 6,710
Estimated Fair Value | Fixed maturities | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,770 2,900
Estimated Fair Value | Fixed maturities | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 3,149 2,538
Estimated Fair Value | Fixed maturities | Commercial mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 838 1,058
Estimated Fair Value | Fixed maturities | Residential mortgage backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,386 1,079
Estimated Fair Value | Fixed maturities | Municipal bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 175 263
Estimated Fair Value | Short-term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,788 2,784
Estimated Fair Value | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 1,715 1,675
Estimated Fair Value | Derivative instruments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 271 206
Estimated Fair Value | Fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 2,892 3,065
Estimated Fair Value | Fair value option | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 988 832
Estimated Fair Value | Fair value option | U.S. government and government agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 6 14
Estimated Fair Value | Fair value option | Asset backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value   0
Estimated Fair Value | Fair value option | Non-U.S. government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 15 8
Estimated Fair Value | Fair value option | Short term investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 68 70
Estimated Fair Value | Fair value option | Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 5 6
Estimated Fair Value | Fair value option | Other investments fair value option    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 423 752
Estimated Fair Value | Fair value option | Other investments measured at net asset value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value [1] $ 1,387 $ 1,383
[1] In accordance with applicable accounting guidance, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheets.
v3.25.2
Fair Value - Rollforward of Level 3 assets and liabilities (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Purchases, issuances, sales and settlements        
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Net realized gains (losses) Net realized gains (losses) Net realized gains (losses) Net realized gains (losses)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Net realized gains (losses) Net realized gains (losses) Net realized gains (losses) Net realized gains (losses)
Recurring | Other liabilities        
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period $ (34) $ (22) $ (73) $ (22)
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 2 (1)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income (2) 0 (2) 1
Purchases, issuances, sales and settlements        
Purchases 0 0 0 0
Issuances 0 (13) 0 (13)
Sales 0 0 0 0
Settlements 16 0 53 0
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period (20) (35) (20) (35)
Recurring | Available for sale | Structured securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period [2] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in earnings [1],[2] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income [2] 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases [2] 14 0 14 0
Issuances [2] 0 0 0 0
Sales [2] 0 0 0 0
Settlements [2] (2) 0 (2) 0
Transfers in and/or out of Level 3 [2] 5 0 5 0
Balance at end of period [2] 17 0 17 0
Recurring | Available for sale | Corporate bonds        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 150 160 97 147
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 2
Purchases, issuances, sales and settlements        
Purchases 0 0 0 98
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements (5) 0 (22) (87)
Transfers in and/or out of Level 3 0 0 70 0
Balance at end of period 145 160 145 160
Recurring | Available for sale | Short-term investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 0 97 0 84
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 1
Purchases, issuances, sales and settlements        
Purchases 0 0 0 12
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements 0 0 0 0
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period 0 97 0 97
Recurring | Fair value option | Other investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 206 126 189 106
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 (4)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 44 30 96 60
Issuances 0 0 0 0
Sales (3) (2) (3) (2)
Settlements (39) (10) (74) (16)
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period 208 144 208 144
Recurring | Fair value option | Short term investments        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 29 17 33 10
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 18 3 24 10
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements (2) (6) (12) (6)
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period 45 14 45 14
Recurring | Fair value option | Equity securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 4 4 4 4
Total gains or (losses) (realized/unrealized) - included in earnings [1] 1 0 1 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 0 0 0 0
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements 0 0 0 0
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period 5 4 5 4
Recurring | Equity securities        
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at beginning of period 7 5 7 5
Total gains or (losses) (realized/unrealized) - included in earnings [1] 0 0 0 0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income 0 0 0 0
Purchases, issuances, sales and settlements        
Purchases 1 1 1 1
Issuances 0 0 0 0
Sales 0 0 0 0
Settlements 0 0 0 0
Transfers in and/or out of Level 3 0 0 0 0
Balance at end of period $ 8 $ 6 $ 8 $ 6
[1] Gains or losses were included in net realized gains (losses).
[2] Includes asset backed securities, mortgage backed securities and commercial mortgage backed securities.
v3.25.2
Fair Value - Narrative (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Fair Value Disclosures [Abstract]    
Total assets and liabilities measured at fair value $ 38,200 $ 35,000
Total assets and liabilities measured at fair value priced using non-binding broker quotes $ 257 $ 185
Total assets and liabilities measured at fair value priced using non-binding broker quotes (percentage) 0.70% 0.50%
Senior notes $ 2,728 $ 2,728
Estimated fair value of senior notes $ 2,500 $ 2,400
v3.25.2
Derivative Instruments - Fair value and notional amount of derivatives (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Derivative offsetting    
Derivative assets subject to master netting agreements $ 271 $ 206
Derivative liabilities subject to master netting agreements $ 159 $ 115
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other assets Other assets
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Other liabilities Other liabilities
Not designated as hedging instrument    
Derivative [Line Items]    
Asset derivatives - fair value $ 271 $ 206
Liability derivatives - fair value (159) (115)
Not designated as hedging instrument | Futures contracts    
Derivative [Line Items]    
Asset derivatives - fair value [1] 110 78
Liability derivatives - fair value [1] (11) (46)
Net derivatives - notional value [2] 8,208 4,781
Not designated as hedging instrument | Foreign currency forward contracts    
Derivative [Line Items]    
Asset derivatives - fair value [1] 92 90
Liability derivatives - fair value [1] (62) (48)
Net derivatives - notional value [2] 2,123 1,698
Not designated as hedging instrument | Other    
Derivative [Line Items]    
Asset derivatives - fair value [1],[3] 69 38
Liability derivatives - fair value [1],[3] (86) (21)
Net derivatives - notional value [2],[3] $ 2,073 $ 236
[1] The fair value of asset derivatives are included in ‘other assets’ and the fair value of liability derivatives are included in ‘other liabilities.’
[2] Represents the absolute notional value of all outstanding contracts, consisting of long and short positions.
[3] Includes swaps, options and other derivatives contracts.
v3.25.2
Derivative Instruments - Summary of net realized gains (losses) recorded in the consolidated statements of income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Net realized gains (losses) on derivative instruments        
Net realized gains (losses) on derivative instruments [1] $ 163 $ 1 $ 262 $ (9)
Not designated as hedging instrument        
Net realized gains (losses) on derivative instruments        
Net realized gains (losses) on derivative instruments 163 1 262 (9)
Not designated as hedging instrument | Futures contracts        
Net realized gains (losses) on derivative instruments        
Net realized gains (losses) on derivative instruments 93 (3) 139 (17)
Not designated as hedging instrument | Foreign currency forward contracts        
Net realized gains (losses) on derivative instruments        
Net realized gains (losses) on derivative instruments 53 2 83 1
Not designated as hedging instrument | Other        
Net realized gains (losses) on derivative instruments        
Net realized gains (losses) on derivative instruments [2] $ 17 $ 2 $ 40 $ 7
[1] See note 10 for information on the Company’s derivative instruments.
[2] Includes realized gains or losses on swaps, options and other derivatives contracts
v3.25.2
Commitments and Contingencies (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]      
Investment commitments $ 4,300   $ 4,400
Interest paid $ 64 $ 63  
v3.25.2
Variable Interest Entities (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Variable Interest Entity [Line Items]    
Total VIE Assets $ 78,788 $ 70,906
Variable Interest Entity, Not Primary Beneficiary    
Variable Interest Entity [Line Items]    
Total VIE Assets 654 1,094
Remaining Coverage, Amount 218  
Variable Interest Entity, Not Primary Beneficiary | 2021-3 Ltd. (Sep-21)    
Variable Interest Entity [Line Items]    
Total VIE Assets 205 363
Remaining Coverage, Amount [1] 19  
Variable Interest Entity, Not Primary Beneficiary | 2022-1 Ltd. (Jan-22)    
Variable Interest Entity [Line Items]    
Total VIE Assets 59 202
Remaining Coverage, Amount [1] 14  
Variable Interest Entity, Not Primary Beneficiary | 2022-2 Ltd. (Sep-22)    
Variable Interest Entity [Line Items]    
Total VIE Assets 53 180
Remaining Coverage, Amount [1] 100  
Variable Interest Entity, Not Primary Beneficiary | 2023-1 Ltd. (Oct-23)    
Variable Interest Entity [Line Items]    
Total VIE Assets 174 186
Remaining Coverage, Amount [1] 44  
Variable Interest Entity, Not Primary Beneficiary | 2024-1 Ltd. (Aug-24)    
Variable Interest Entity [Line Items]    
Total VIE Assets 163 $ 163
Remaining Coverage, Amount $ 41  
[1] Coverage from a separate panel of reinsurers remaining at June 30, 2025.
v3.25.2
Other Comprehensive Income (Loss) - Amounts reclassified from accumulated other comprehensive income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Net realized gains (losses) $ 229 $ 122 $ 232 $ 189
Provision for credit losses (8) 4 (8) (2)
Income (loss) before income taxes and income (loss) from operating affiliates 1,411 1,321 2,089 2,487
Income tax (expense) benefit (214) (97) (335) (198)
Net of tax 1,237 1,269 1,811 2,389
Reclassification out of accumulated other comprehensive income | Unrealized appreciation (decline) on available-for-sale investments        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Net realized gains (losses) 14 (64) (49) (92)
Provision for credit losses (8) 4 (8) (2)
Income (loss) before income taxes and income (loss) from operating affiliates 6 (60) (57) (94)
Income tax (expense) benefit 1 7 12 12
Net of tax $ 7 $ (53) $ (45) $ (82)
v3.25.2
Other Comprehensive Income (Loss) - Components of other comprehensive income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Before tax amount:        
Unrealized holding gains (losses) arising during period, before tax $ 304 $ (36) $ 549 $ (187)
Less reclassification of net realized gains included in net income, before tax 6 (60) (57) (94)
Foreign currency translation adjustments, before tax 62 (16) 88 (49)
Other comprehensive income (loss), before tax 360 8 694 (142)
Tax expense (benefit):        
Unrealized holding gains (losses) arising during period, tax 1 (10) 12 (20)
Less reclassification of net realized gains included in net income, tax (1) (7) (12) (12)
Foreign currency translation adjustments, tax (2) 0 (2) 0
Other comprehensive income (loss), tax 0 (3) 22 (8)
Net of tax amount:        
Unrealized holding gains (losses) arising during period, net of tax 303 (26) 537 (167)
Less reclassification of net realized gains included in net income, net of tax 7 (53) (45) (82)
Foreign currency translation adjustments, net of tax 64 (16) 90 (49)
Net current period other comprehensive income (loss) $ 360 $ 11 $ 672 $ (134)
v3.25.2
Income Taxes (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Income Tax Disclosure [Abstract]      
Effective tax rate on income before income taxes (percentage) 15.60% 7.70%  
Net deferred tax asset $ 1,500   $ 1,600
Income taxes paid (received) $ 149 $ 145  
v3.25.2
Transactions With Related Parties (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Mar. 31, 2025
Dec. 31, 2024
Mar. 31, 2024
Dec. 31, 2023
Related Party Transaction [Line Items]                
Net premiums written $ 4,348 $ 3,781 $ 8,863 $ 7,866        
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses 9,044 $ 7,473 9,044 7,473 $ 8,969 $ 8,260 $ 7,509 $ 7,064
Reinsurance balances payable 2,841   2,841     2,137    
Other assets 6,684   6,684     6,231    
Other liabilities 3,225   3,225     3,039    
Operating affiliates | Premia                
Related Party Transaction [Line Items]                
Funds held asset 127   127     137    
Operating affiliates | Somers                
Related Party Transaction [Line Items]                
Net premiums written     419 $ 428        
Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses 1,800   1,800     1,600    
Reinsurance balances payable 602   602     $ 489    
Equity Method Investee | Greysbridge Holdings Ltd                
Related Party Transaction [Line Items]                
Other assets 290   290          
Other liabilities $ 290   $ 290          
v3.25.2
Subsequent Events (Details) - Authorized Share Repurchase Program - USD ($)
$ in Millions
 1 Months Ended 6 Months Ended
Aug. 05, 2025
Jun. 30, 2025
Jun. 30, 2024
Common shares      
Subsequent Event [Line Items]      
Treasury stock, shares acquired (shares)   4,100,000 0
Aggregate cost of shares repurchased   $ 359.7  
Remaining authorized repurchase amount   $ 637.1  
Subsequent Event      
Subsequent Event [Line Items]      
Treasury stock, shares acquired (shares) 2,800,000    
Aggregate cost of shares repurchased $ 244.0    
Remaining authorized repurchase amount $ 393.0