ALPHA & OMEGA SEMICONDUCTOR LTD, 10-Q filed on 2/9/2017
Quarterly Report
v3.6.0.2
Document and Entity Information - shares
6 Months Ended
Dec. 31, 2016
Jan. 31, 2017
Document and Entity Information [Abstract]    
Entity Registrant Name ALPHA & OMEGA SEMICONDUCTOR Ltd  
Entity Central Index Key 0001387467  
Current Fiscal Year End Date --06-30  
Entity Filer Category Accelerated Filer  
Document Type 10-Q  
Document Period End Date Dec. 31, 2016  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   23,605,765
v3.6.0.2
CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Current assets:    
Cash and cash equivalents $ 122,793 $ 87,774
Restricted cash 324 188
Accounts receivable, net 24,482 26,594
Inventories 70,239 68,848
Other current assets 5,762 4,526
Total current assets 223,600 187,930
Property, plant and equipment, net 122,686 116,084
Deferred income tax assets - long term 5,502 12,132
Other long-term assets 10,240 2,359
Total assets 362,028 318,505
Current liabilities:    
Accounts payable 38,010 42,718
Accrued liabilities 25,099 22,590
Income taxes payable 2,583 2,356
Deferred margin 955 997
Capital leases 809 819
Total current liabilities 67,456 69,480
Income taxes payable - long term 1,608 1,577
Deferred income tax liabilities 2,924 2,973
Capital leases - long term 1,296 1,695
Other long term liabilities 623 741
Total liabilities 73,907 76,466
Commitments and contingencies (Note 9)
Preferred shares, par value $0.002 per share:    
Authorized: 10,000 shares, issued and outstanding: none at December 31, 2016 and June 30, 2016 0 0
Common shares, par value $0.002 per share:    
Authorized: 50,000 shares, issued and outstanding: 29,214 shares and 23,594 shares, respectively at December 31, 2016 and 28,405 shares and 22,754 shares, respectively at June 30, 2016 58 57
Treasury shares at cost, 5,620 shares at December 31, 2016 and 5,651 shares at June 30, 2016 (49,934) (50,199)
Additional paid-in capital 202,370 191,444
Accumulated other comprehensive income (loss) (422) 769
Retained earnings 106,284 100,071
Total Alpha and Omega Semiconductor Limited shareholder's equity 258,356 242,142
Noncontrolling interest 29,765 (103)
Total equity 288,121 242,039
Total liabilities and equity $ 362,028 $ 318,505
v3.6.0.2
CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Dec. 31, 2016
Jun. 30, 2016
Common shares, par value (in dollars per share) $ 0.002 $ 0.002
Common shares, authorized (in shares) 50,000,000 50,000,000
Common stock, shares issued (in shares) 29,214,000 28,405,000
Common stock, shares outstanding (in shares) 23,594,000 22,754,000
Preferred stock, par value (in dollars per share) $ 0.002 $ 0.002
Preferred stock, shares authorized (in shares) 10,000,000 10,000,000
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Treasury shares (in shares) 5,620,000 5,651,000
v3.6.0.2
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)
shares in Thousands, $ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Revenue $ 94,687 $ 79,825 $ 192,049 $ 161,264
Cost of goods sold 72,593 64,853 148,011 131,231
Gross profit 22,094 14,972 44,038 30,033
Operating expenses        
Research and development 7,284 5,941 14,303 12,105
Selling, general and administrative 11,974 8,872 23,157 18,369
Impairment of long-lived assets 0 432 0 432
Total operating expenses 19,258 15,245 37,460 30,906
Operating income (loss) 2,836 (273) 6,578 (873)
Interest income and other income (loss), net (70) (316) (119) (467)
Interest expense (24) (7) (50) (17)
Net Income (loss) before income taxes 2,742 (596) 6,409 (1,357)
Income tax expense 1,085 1,015 2,322 2,229
Net income (loss) including noncontrolling interest 1,657 (1,611) 4,087 (3,586)
Net loss attributable to noncontrolling interest (1,190) 0 (2,067) 0
Net income (loss) attributable to Alpha and Omega Semiconductor Limited $ 2,847 $ (1,611) $ 6,154 $ (3,586)
Net income (loss) per common share attributable to Alpha and Omega Semiconductor Limited        
Basic (in dollars per share) $ 0.12 $ (0.07) $ 0.26 $ (0.16)
Diluted (in dollars per share) $ 0.11 $ (0.07) $ 0.25 $ (0.16)
Weighted average number of common shares attributable to Alpha and Omega Semiconductor Limited used to compute net income (loss) per share        
Basic (in shares) 23,481 22,269 23,256 22,483
Diluted (in shares) 24,977 22,269 24,695 22,483
v3.6.0.2
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Net income (loss) including noncontrolling interest $ 1,657 $ (1,611) $ 4,087 $ (3,586)
Net income (loss) attributable to Alpha and Omega Semiconductor Limited 2,847 (1,611) 6,154 (3,586)
Foreign currency translation adjustment (2,326) 11 (2,256) (155)
Comprehensive income (loss) (669) (1,600) 1,831 (3,741)
Noncontrolling interest (2,234) 0 (3,132) 0
Comprehensive income (loss) attributable to Alpha and Omega Semiconductor Limited $ 1,565 $ (1,600) $ 4,963 $ (3,741)
v3.6.0.2
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)
$ in Thousands
6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Cash flows from operating activities    
Net income (loss) including noncontrolling interest $ 4,087 $ (3,586)
Adjustments to reconcile net loss to net cash provided by operating activities:    
Depreciation and amortization 13,263 13,778
Share-based compensation expense 2,870 1,874
Deferred income taxes, net 6,581 506
Gain on disposal of property and equipment (370) 0
Impairment of long-lived assets 0 432
Changes in assets and liabilities:    
Accounts receivable 2,112 12,727
Inventories (1,391) 3,073
Other current and long-term assets (7,032) 831
Accounts payable (4,605) (6,454)
Income taxes payable 257 364
Accrued and other liabilities 2,297 1,086
Net cash provided by operating activities 18,069 24,631
Cash flows from investing activities    
Purchases of property and equipment (23,740) (10,770)
Proceeds from sale of property and equipment 411 0
(Increase) decrease in restricted cash (135) 137
Net cash used in investing activities (23,464) (10,633)
Cash flows from financing activities    
Proceeds from investment by noncontrolling interest 33,000 0
Withholding tax on restricted stock units (348) (189)
Proceeds from exercise of stock options and ESPP 8,729 2,772
Payment for repurchases of common shares 0 (40,257)
Principal payments on capital leases (408) (456)
Net cash provided by (used in) financing activities 40,973 (38,130)
Effect of exchange rate changes on cash and cash equivalents (559) (95)
Net increase (decrease) in cash and cash equivalents 35,019 (24,227)
Cash and cash equivalents at beginning of period 87,774 106,085
Cash and cash equivalents at end of period 122,793 81,858
Supplemental disclosures of non-cash investing and financing information:    
Property and equipment purchased but not yet paid 5,153 1,645
Re-issuance of treasury stock $ 59 $ 43
v3.6.0.2
The Company and Significant Accounting Policies
6 Months Ended
Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
The Company and Significant Accounting Policies
The Company and Significant Accounting Policies
The Company
Alpha and Omega Semiconductor Limited and its subsidiaries (the “Company,” "AOS," "we" or "us") design, develop and supply a broad range of power semiconductors. The Company's portfolio of products targets high-volume applications, including personal computers, flat panel TVs, LED lighting, smart phones, battery packs, consumer and industrial motor controls and power supplies for TVs, computers, servers and telecommunications equipment. The Company conducts its operations primarily in the United States of America (“USA”), Hong Kong, China, Taiwan, Korea and Japan.
Basis of Preparation
The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2016. All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the periods presented have been included in the interim periods. Operating results for the six months ended December 31, 2016 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2017. The condensed consolidated balance sheet at June 30, 2016 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2016.

Reclassification

The Company has reclassified certain amounts previously reported in its financial statements to conform to the current presentation. These reclassifications did not have a material impact on our consolidated financial statements.

Joint Venture

In March 2016, the Company executed an agreement with two strategic investment funds owned by the Municipality of Chongqing, China (the "Chongqing Funds") to form a joint venture for a new state-of-the-art power semiconductor packaging, testing and wafer fabrication facility in Liangjiang New Area of Chongqing (the "Joint Venture"). The initial capitalization of the Joint Venture under the agreement is $330.0 million, which includes cash contributions from the Chongqing Funds and contributions of cash, equipment and intangible assets from the Company. The Company owns 51% and the Chongqing Funds owns 49% of the equity interest of the Joint Venture. The financial statements of the Joint Venture are consolidated in the financial statements of the company because the Company has a controlling financial interest.
Use of Estimates
The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, share-based compensation, and useful lives for property, plant and equipment and intangible assets.
Fair Value of Financial Instruments
The fair values of cash equivalents are based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities.

Impairment of Long-Lived Assets

Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Factors that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or any other significant adverse change that would indicate that the carrying amount of an asset or group of assets may not be recoverable. Where such factors indicate potential impairment, the recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life.  The impairment loss is measured based on the difference between the carrying amount and the estimated fair value.
Comprehensive Income (Loss)
Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss).

Recent Accounting Pronouncements
    
In November 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-18, "Statement of Cash Flows: Restricted Cash ("ASU 2016-18"). ASU 2016-18 requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. This ASU will be effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted and requires retrospective adoption.  The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows.

In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"). ASU 2016-16 requires entities to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amended guidance is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods wihin annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-16 will have on its consolidated financial statements.

In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). ASU 2016-15 identifies how certain cash receipts and cash payments are presented and classified in the Statement of Cash Flows under Topic 230. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted.  Upon adoption, entities must apply the guidance retrospectively to all periods presented. The Company is currently evaluating the impact the adoption of ASU 2016-15 will have on its consolidated financial statements.

In May 2016, the FASB issued Accounting Standards Update ("ASU") 2016-12, "Revenue from Contracts with Customers (Topic 606) - Narrow-Scope Improvements and Practical Expedients." ASU 2016-12 provides additional guidance established by the FASB-IASB Joint Transition Resource Group for Revenue Recognition regarding the implementation of certain aspects of the new revenue recognition guidance. More specifically, the amendment provides additional guidance regarding assessing the collectibility criterion, the presentation of sales taxes and other similar taxes collected from customers, noncash consideration, contract modifications or completed contracts at transition of the new revenue recognition guidance and technical corrections. The effective date is consistent with the effective date of ASU 2014-09. The Company is currently evaluating the impact the adoption of ASU 2016-12 will have on its consolidated financial statements. The Company does not plan to early adopt this standard.

In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10"). ASU 2016-10 clarifies two aspects of Topic 606: (a) identifying performance obligations; and (b) the licensing implementation guidance. The update is effective for annual periods beginning after December 15, 2017 including interim reporting periods therein. The Company is currently evaluating the impact the adoption of ASU 2016-10 will have on its consolidated financial statements.

In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 simplifies several aspects of the accounting for employee share-based payment transactions including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. This guidance is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows.

In February 2016, the FASB issued No. 2016-02, Leases ("ASU 2016-02"). This guidance requires a dual approach for lessee accounting under which a lessee will account for leases as finance leases or operating leases. Both finance and operating leases will result in the lessee recognizing a right-of-use asset and a corresponding liability on its balance sheet, with differing methodology for income statement recognition. This guidance is effective for public business entities for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. A modified retrospective approach is required for all leases existing or entered into after the beginning of the earliest comparative period in the consolidated financial statements. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. In August 2015, the FASB issued an accounting standard update for a one-year deferral of the effective date of ASU 2014-09 to annual and interim periods beginning after December 15, 2017 and permits entities to early adopt the standard of ASU 2014-09 for annual and interim reporting periods beginning after December 15, 2016. Companies are permitted to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment.  The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements.
v3.6.0.2
Net Income (Loss) Per Share
6 Months Ended
Dec. 31, 2016
Earnings Per Share [Abstract]  
Net Income (Loss) Per Share
Net Income (Loss) Per Common Share Attributable to Alpha and Omega Semiconductor Limited
The following table presents the calculation of basic and diluted net income (loss) per share attributable to common shareholders:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands, except per share data)
Numerator:
 
 
 
 
 
 
 
Net income (loss) attributable to Alpha and Omega Semiconductor Limited
$
2,847

 
$
(1,611
)
 
$
6,154

 
$
(3,586
)
 
 
 
 
 
 
 
 
Denominator:
 
 
 
 
 
 
 
Basic:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income (loss) per share
23,481

 
22,269

 
23,256

 
22,483

Diluted:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income (loss) per share
23,481

 
22,269

 
23,256

 
22,483

Effect of potentially dilutive securities:
 
 
 
 
 
 
 
Stock options, RSUs and ESPP shares
1,496

 

 
1,439

 

Weighted average number of common shares used to compute diluted net income (loss) per share
24,977

 
22,269

 
24,695

 
22,483

Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited:
 
 
 
 
 
 
 
Basic
$
0.12

 
$
(0.07
)
 
$
0.26

 
$
(0.16
)
Diluted
$
0.11

 
$
(0.07
)
 
$
0.25

 
$
(0.16
)

The following potential dilutive securities were excluded from the computation of diluted net income (loss) per share as their effect would have been anti-dilutive:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Employee stock options and RSUs

 
3,299

 
123

 
3,458

ESPP
16

 
551

 
8

 
369

Total potential dilutive securities
16

 
3,850

 
131

 
3,827

v3.6.0.2
Concentration of Credit Risk and Significant Customers
6 Months Ended
Dec. 31, 2016
Risks and Uncertainties [Abstract]  
Concentration of Credit Risk and Significant Customers
Concentration of Credit Risk and Significant Customers
The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application and review of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers.
Credit sales, which are mainly on credit terms of 30 to 60 days, are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its trade accounts receivable to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.
Summarized below are individual customers whose revenue or accounts receivable balances were more than 10% of the respective total consolidated amounts:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
Percentage of revenue
2016
 
2015
 
2016
 
2015
Customer A
27.0
%
 
24.0
%
 
25.6
%
 
23.6
%
Customer B
35.8
%
 
39.6
%
 
36.2
%
 
37.8
%
Customer C
10.7
%
 
10.8
%
 
12.3
%
 
12.6
%

 
December 31,
2016
 
June 30,
2016
Percentage of accounts receivable
 
Customer A
35.8
%
 
21.3
%
Customer B
9.6
%
 
16.7
%
Customer C
24.7
%
 
27.2
%
v3.6.0.2
Balance Sheet Components
6 Months Ended
Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]  
Balance Sheet Components
Balance Sheet Components
Accounts receivable:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Accounts receivable
$
42,109

 
$
43,324

Less: Allowance for price adjustments
(17,597
)
 
(16,700
)
Less: Allowance for doubtful accounts
(30
)
 
(30
)
Accounts receivable, net
$
24,482

 
$
26,594



Inventories:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Raw materials
$
25,622

 
$
23,982

Work in-process
34,369

 
32,446

Finished goods
10,248

 
12,420

 
$
70,239

 
$
68,848


 
Property, plant and equipment, net:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Land
$
4,877

 
$
4,877

Building
4,325

 
4,323

Manufacturing machinery and equipment
201,425

 
193,164

Equipment and tooling
13,185

 
12,289

Computer equipment and software
23,921

 
23,448

Office furniture and equipment
1,943

 
1,822

Leasehold improvements
28,896

 
28,660

 
278,572

 
268,583

Less: Accumulated depreciation
(179,760
)
 
(168,687
)
 
98,812

 
99,896

Equipment and construction in progress
23,874

 
16,188

Property, plant and equipment, net
$
122,686

 
$
116,084


Other long-term assets:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Prepayments for property and equipment
$
2,087

 
$
506

Prepayment for others
226

 
42

Prepaid income tax
4,998

 

Investment in a privately held company
100

 
100

Office leases deposits
2,546

 
1,427

Intangible assets
14

 
15

Goodwill
269

 
269

 
$
10,240

 
$
2,359


Accrued liabilities:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Accrued compensation and benefit
$
13,457

 
$
10,211

Warranty accrual
2,382

 
1,495

Stock rotation accrual
1,707

 
1,988

Accrued professional fees
1,741

 
1,867

Accrued inventory
448

 
918

Accrued facilities related expenses
1,269

 
1,544

Other accrued expenses
4,095

 
4,567

 
$
25,099

 
$
22,590





The activities in the warranty accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2016
 
2015
 
(in thousands)
Beginning balance
$
1,495

 
$
1,957

Additions
1,040

 
747

Utilization
(153
)
 
(1,108
)
Ending balance
$
2,382

 
$
1,596


The activities in the stock rotation accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2016
 
2015
 
(in thousands)
Beginning balance
$
1,988

 
$
1,894

Additions
3,008

 
3,120

Utilization
(3,289
)
 
(3,142
)
Ending balance
$
1,707

 
$
1,872


Other Long-term liabilities:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Deferred rent
$
623

 
$
741

v3.6.0.2
Joint Venture
6 Months Ended
Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]  
Joint Venture
5. Joint Venture

On March 29, 2016, the Company entered into a joint venture contract (the “JV Agreement”) with two investment funds owned by the Municipality of Chongqing (the “Chongqing Funds”), pursuant to which the Company and the Chongqing Funds formed a joint venture, (the “JV Company”), for the purpose of constructing a power semiconductor packaging, testing and 12-inch wafer fabrication facility in the Liangjiang New Area of Chongqing, China (the “JV Transaction”). The total initial capitalization of the JV Company is $330.0 million (the “Initial Capitalization”), which includes cash contribution from the Chongqing Funds and contributions of cash, equipments and intangible assets from the Company.  The Initial Capitalization will be completed in stages commencing on the incorporation of the JV Company.  The Company owns 51%, and the Chongqing Funds owns 49%, of the equity interest in the JV Company. If both parties agree that the termination of the JV Company is the best interest of each party or the JV Company is bankrupt or insolvent where either party may terminate early, after paying the debts of the JV Company, the remaining assets of the JV Company shall be paid to the Chongqing Funds to cover the principal of its total paid-in contributions plus interest at 10% simple annual rate prior to distributing the balance of the JV Company's assets to the Company. The Company expects the JV Company to commence its initial production in the first half of fiscal 2018.

As part of the JV Transaction, the JV Company entered into an Engineering, Procurement and Construction Contract (the “EPC Contract”) with The IT Electronics Eleventh Design & Research Institute Scientific and Technological Engineering Corporation Limited (the “Contractor”), effective as of January 10, 2017 (the "Effective Date"), pursuant which the Contractor was engaged to construct the manufacturing facility contemplated under the JV Agreement. Under the EPC Contract, the Contractor’s obligations include, but are not limited to: (i) the development of conceptual design, initial design, construction drawing design and optimization, and submission of such designs to the JV Company for examination and confirmation; and (ii) the construction of the assembly and wafer fabrication facilities and related procurement services, including the selection and engagement of subcontractors, in accordance with a construction schedule agreed upon by the parties. The total price payable under the EPC Contract is Chinese Renminbi (RMB) 540,000,000, or approximately $77,996,360 based on the currency exchange rate between RMB and U.S. Dollars on the Effective Date, which consists of $2,820,154 (RMB 19,525,052) of design fees (“Design Fees”) and $75,176,206 (RMB 520,474,948) of construction and procurement fees (including compliance with safety and aesthetic requirements) (“Construction Fees”). The Design Fees and Construction Fees will be paid by the JV Company pursuant to a payment schedule based on the progress of the construction and the achievements of specified milestones, approximately $58.3 million and $19.7 million in calendar year 2017 and 2018, respectively. The payment may be subject to volatility as a result of exposure to fluctuations in RMB foreign exchange rates.

The Company began consolidating the financial statements of the JV Company in the quarter ended June 30, 2016. During the quarter ended September 30, 2016, the Chongqing Funds contributed $33.0 million of initial capital in cash and the Company fulfilled its obligation to contribute certain packaging equipments as required by the JV Agreement by transferring the legal titles of such equipment to the JV Company. Within one year from June 30, 2016, the Company expects to contribute certain intangible assets and cash of $10.0 million pursuant to the terms of the JV Agreement.

The changes in total stockholders' equity and noncontrolling interest were as follows (in thousands):

 
 
Total AOS Stockholders' Equity
 
Noncontrolling Interest
 
Total Equity
Balance, June 30, 2016
 
$
242,142

 
$
(103
)
 
$
242,039

     Contributions from noncontrolling interest
 

 
33,000

 
33,000

Exercise of common stock options and release of RSUs
 
7,239

 

 
7,239

Issuance of shares under ESPP
 
1,166

 

 
1,166

Reissuance of treasury stock upon exercise of common stock options and release of RSUs
 
324

 

 
324

Withholding tax on restricted stock units
 
(348
)
 

 
(348
)
     Stock-based compensation expense
 
2,870

 

 
2,870

      Net income (loss)
 
6,154

 
(2,067
)
 
4,087

     Cumulative translation adjustment
 
(1,191
)
 
(1,065
)
 
(2,256
)
Balance, December 31, 2016
 
$
258,356

 
$
29,765

 
$
288,121

v3.6.0.2
Shareholders' Equity and Share-based Compensation
6 Months Ended
Dec. 31, 2016
Share-based Compensation [Abstract]  
Shareholders' Equity and Share-based Compensation
Shareholders' Equity and Share-based Compensation
Share Repurchase

In April 2015, the Board of Directors approved an increase in the remaining available amount under the Company’s then effective share repurchase program from approximately $17.8 million to $50.0 million. The repurchases may be made from the open market pursuant to a pre-established Rule 10b5-1 trading plan (as amended, the "Repurchase Trading Plan") or through privately negotiated transactions.

In July 2015, the Company completed a Dutch tender offer (the "Tender Offer") in which it purchased 3,296,703 shares of its common shares, at a purchase price of $9.10 per share, for an aggregate purchase price of $30.0 million, excluding fees and expenses relating to the Tender Offer. The Tender Offer was part of the $50.0 million share repurchase program approved by the Board on April 15, 2015. Shares repurchased are accounted for as treasury shares and the total cost of shares repurchased is recorded as a reduction of shareholders' equity.

During the six months ended December 31, 2016, the Company did not repurchase any shares pursuant to the repurchase program.  Since the inception of the program in 2010, the Company repurchased an aggregate of 5,723,093 shares from the open market for a total cost of $50.8 million, at an average price of $8.87 per share, excluding fees and related expenses.  No repurchased shares have been retired. Of the 5,723,093 repurchased shares, 103,003 shares with a weighted average repurchase price of $11.17 per share, were reissued at an average price of $6.13 per share pursuant to option exercises and vested restricted share units. As of December 31, 2016, $6.4 million remained available under the share repurchase program.

Shelf Registration

In January 2017, the Company filed a shelf registration statement on Form S-3/A with the U.S. Securities and Exchange Commission through which it may offer and sell from time to time shares of common shares, shares of preferred shares, debt securities or warrants to purchase shares of common shares or shares of preferred shares, or units. Under this shelf registration statement, it may sell any combination of the above described securities, in one or more offerings in amounts, at prices and on terms to be determined at the time of the offering for an aggregate offering price of up to $250.0 million.
Stock Options
The Company did not grant any stock options during the six months ended December 31, 2016. Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.
The following table summarizes the Company's stock option activities for the six months ended December 31, 2016:
 
 
 
 
 
Weighted
 
 
 
 
 
Weighted
 
Average
 
 
 
 
 
Average
 
Remaining
 
 
 
Number of
 
Exercise Price
 
Contractual
 
Aggregate
 
Shares
 
Per Share
 
Term (in years)
 
Intrinsic Value
Outstanding at June 30, 2016
1,859,260

 
$
11.37

 
4.71
 
$
5,959,720

Granted

 
$

 
 
 
 
Exercised
(637,406
)
 
$
11.87

 
 
 
$
5,189,023

Canceled or forfeited
(90,000
)
 
$
12.63

 
 
 
 
Outstanding at December 31, 2016
1,131,854

 
$
11.00

 
4.93
 
$
11,625,154

Options vested and expected to vest
1,121,561

 
$
11.03

 
4.91
 
$
11,484,305

Exercisable at December 31, 2016
951,973

 
$
11.65

 
4.50
 
$
9,162,612


Restricted Stock Units ("RSU")
The following table summarizes the Company's RSU activities for the six months ended December 31, 2016:
 
Number of Restricted Stock
Units
 
Weighted Average
Grant Date Fair
Value Per Share
 
Weighted Average
Remaining
Recognition
Period (Years)
 
Aggregate Intrinsic Value
Nonvested at June 30, 2016
933,063

 
$
9.18

 
1.73
 
$
12,997,568

Granted
109,617

 
$
20.18

 
 
 
 
Vested
(78,235
)
 
$
9.40

 
 
 
 
Forfeited
(18,725
)
 
$
10.94

 
 
 
 
Nonvested at December 31, 2016
945,720

 
$
10.40

 
1.40
 
$
20,115,464

RSUs vested and expected to vest
829,631

 
 
 
1.30
 
$
17,646,257

The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.
Employee Share Purchase Plan ("ESPP")
The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows:
 
 
 
Six Months Ended December 31,
 
2016
Volatility rate
39.09%
Risk-free interest rate
0.6% - 1.0%
Expected term
1.3 years
Dividend yield
0%

Share-based Compensation Expense
The total share-based compensation expense related to stock options, RSUs and ESPP described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Cost of goods sold
$
205

 
$
157

 
$
400

 
$
288

Research and development
383

 
264

 
743

 
457

Selling, general and administrative
966

 
664

 
1,727

 
1,129

 
$
1,554

 
$
1,085

 
$
2,870

 
$
1,874


As of December 31, 2016, total unrecognized compensation cost under the Company's equity plans was $5.4 million, which is expected to be recognized over a weighted-average period of 1.3 years.
v3.6.0.2
Income Taxes
6 Months Ended
Dec. 31, 2016
Income Tax Disclosure [Abstract]  
Income Taxes
Income Taxes
The Company recognized income tax expense of approximately $1.1 million and $1.0 million for the three months ended December 31, 2016 and 2015, respectively. The Company recognized income tax expense of approximately $2.3 million and $2.2 million for the six months ended December 31, 2016 and 2015, respectively. The estimated effective tax rate for the three months ended December 31, 2016 was 39.6% compared to (170.3)% for the three months ended December 31, 2015. The estimated effective tax rate for the six months ended December 31, 2016 was 36.2% compared to (164.3)% for the six months ended December 31, 2015. The changes in the effective tax rate and tax expense between the periods resulted primarily from changes in the mix of earnings in various geographic jurisdictions between the current quarter and the same period of last year.

During the quarter ended September 30, 2016, the Company fulfilled its obligations to contribute certain packaging equipment as required by the JV Agreement by transferring the legal titles of such equipment to the JV Company. The Company recorded $6.6 million on both deferred tax assets and prepaid tax asset, which is amortized to tax expense over the useful life of the assets. As of December 31, 2016, the prepaid tax asset was amortized down to $6.1 million, of which $1.1 million and $5.0 million were included in prepaid and other current assets and other long-term assets on the Company’s balance sheet, respectively.
The Company files its income tax returns in the United States and in various foreign jurisdictions. The tax years 2001 to 2016 remain open to examination by U.S. federal and state tax authorities. The tax years 2009 to 2016 remain open to examination by foreign tax authorities.
The Company's income tax returns are subject to examinations by the Internal Revenue Service and other tax authorities in various jurisdictions. In accordance with the guidance on the accounting for uncertainty in income taxes, the Company regularly assesses the likelihood of adverse outcomes resulting from these examinations to determine the adequacy of its provision for income taxes. These assessments can require considerable estimates and judgments. As of December 31, 2016, the gross amount of unrecognized tax benefits was approximately $6.9 million, of which $4.5 million, if recognized, would reduce the effective income tax rate in future periods. If the Company's estimate of income tax liabilities proves to be less than the ultimate assessment, then a further charge to expense would be required. If events occur and the payment of these amounts ultimately proves to be unnecessary, the reversal of the liabilities would result in tax benefits being recognized in the period when the Company determines the liabilities are no longer necessary. The Company does not anticipate any material changes to its uncertain tax positions during the next twelve months.

On July 27, 2015, in Altera Corp. v. Commissioner, the U.S. Tax Court issued an opinion related to the treatment of share-based compensation expense in an intercompany cost-sharing arrangement. A final decision has yet to be issued by the Tax Court due to other outstanding issues related to the case. At this time, the U.S. Department of the Treasury has not withdrawn the requirement to include share-based compensation from its regulations. Due to the uncertainty surrounding the status of the current regulations, questions related to the scope of potential benefits, and the risk of the Tax Court’s decision being overturned upon appeal, the Company has not recorded any benefit as of December 31, 2016. The Company will continue to monitor ongoing developments and potential impacts to its financial statements.
v3.6.0.2
Segment and Geographic Information
6 Months Ended
Dec. 31, 2016
Segment Reporting [Abstract]  
Segment and Geographic Information
Segment and Geographic Information
The Company is organized as, and operates in, one operating segment: the design, development and supply of power semiconductor products for computing, consumer electronics, communication and industrial applications. The chief operating decision-maker is the Chief Executive Officer. The financial information presented to the Company's Chief Executive Officer is on a consolidated basis, accompanied by information about revenue by customer and geographic region, for purposes of evaluating financial performance and allocating resources. The Company has one business segment, and there are no segment managers who are held accountable for operations, operating results and plans for products or components below the consolidated unit level. Accordingly, the Company reports as a single operating segment.
The Company sells its products primarily to distributors in the Asia Pacific region, who in turn sell these products to end customers. Because the Company's distributors sell their products to end customers which may have a global presence, revenue by geographical location is not necessarily representative of the geographical distribution of sales to end user markets.
The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Hong Kong
$
78,253

 
$
69,904

 
$
161,088

 
$
140,357

China
14,383

 
7,922

 
26,825

 
16,938

South Korea
393

 
442

 
759

 
1,100

United States
798

 
784

 
1,692

 
1,501

Other Countries
860

 
773

 
1,685

 
1,368

 
$
94,687

 
$
79,825

 
$
192,049

 
$
161,264

The following is a summary of revenue by product type:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Power discrete
$
69,822

 
$
59,392

 
$
141,250

 
$
119,305

Power IC
21,859

 
16,400

 
44,857

 
33,913

Packaging and testing services
3,006

 
4,033

 
5,942

 
8,046

 
$
94,687

 
$
79,825

 
$
192,049

 
$
161,264

 
Long-lived assets, net consisting of property, plant and equipment, by geographical area are as follows:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
China
$
68,639

 
$
64,272

United States
53,432

 
51,214

Other Countries
615

 
598

 
$
122,686

 
$
116,084

v3.6.0.2
Commitments and Contingencies
6 Months Ended
Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies
Commitments and Contingencies
Purchase Commitments
As of December 31, 2016 and June 30, 2016, the Company had approximately $25.9 million and $39.6 million, respectively, of outstanding purchase commitments primarily for purchases of semiconductor raw materials, wafers, spare parts and packaging and testing services, and approximately $10.3 million and $6.6 million, respectively, of capital commitments for the purchase of property and equipment.
Contingencies and Indemnities
The Company is currently not a party to any pending material legal proceedings. The Company has in the past, and may from time to time in the future, become involved in legal proceedings arising from the normal course of business activities.  The semiconductor industry is characterized by frequent claims and litigation, including claims regarding patent and other intellectual property rights as well as improper hiring practices. Irrespective of the validity of such claims, the Company could incur significant costs in the defense of such claims and suffer adverse effects on its operations.
The Company is a party to a variety of agreements that it has contracted with various third parties. Pursuant to these agreements, the Company may be obligated to indemnify another party to such an agreement with respect to certain matters. Typically, these obligations arise in the context of contracts entered into by the Company, under which the Company customarily agrees to hold the other party harmless against losses arising from a breach of representations and covenants related to such matters as title to assets sold, certain intellectual property rights, specified environmental matters and certain income taxes. In these circumstances, payment by the Company is customarily conditioned on the other party making a claim pursuant to the procedures specified in the particular contract, which procedures typically allow the Company to challenge the other party's claim. Further, the Company's obligations under these agreements may be limited in time and/or amount, and in some instances, the Company may have recourse against third parties for certain payments made by it under these agreements. The Company has not historically paid or recorded any material indemnifications and no accrual has been made at December 31, 2016 and June 30, 2016.
The Company has agreed to indemnify its directors and certain employees as permitted by law and pursuant to its bye-laws, and has entered into indemnification agreements with its directors and executive officers. The Company has not recorded a liability associated with these indemnification arrangements, as it historically has not incurred any material costs associated with such indemnification obligations. Costs associated with such indemnification obligations may be mitigated by insurance coverage that the Company maintains. However, such insurance may not cover any, or may cover only a portion of, the amounts the Company may be required to pay. In addition, the Company may not be able to maintain such insurance coverage in the future.

Joint Venture

In March 2016, the Company executed an agreement with two strategic investment funds owned by the Municipality of Chongqing, China to form a joint venture for a new state-of-the-art power semiconductor packaging, testing and wafer fabrication facility in Liangjiang New Area of Chongqing (the "Joint Venture"). The initial capitalization of the Joint Venture under the agreement is $330.0 million, which includes cash contribution from the Chongqing Funds and contributions of cash, equipment and intangible assets from the Company. The Company owns 51% and the Chongqing Funds owns 49% of the equity interest of the Joint Venture. The Joint Venture is accounted under the provisions of the consolidation guidance since the Company has controlling financial interest.

The Joint Venture is expected to commence its initial packaging production in the first half of fiscal 2018. Within one year from June 30, 2016, the Company is expected to contribute cash of $10.0 million and certain intangible assets. Over the long term, the Joint Venture plans to construct a 12-inch wafer fabrication facility for the production of power semiconductors.

In January 2017, the JV Company entered into an Engineering, Procurement and Construction Contract with The IT Electronics Eleventh Design & Research Institute Scientific and Technological Engineering Corporation Limited. The total price payable by the JV Company under the EPC Contract is RMB 540,000,000, or $77,996,360 based on the currency exchange rate between RMB and U.S. Dollars on the Effective Date, which consists of $2,820,154 (RMB 19,525,052) of design fees and $75,176,206 (RMB 520,474,948) of construction and procurement fees, including compliance with safety and aesthetic requirements.
v3.6.0.2
The Company and Significant Accounting Policies (Policies)
6 Months Ended
Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Basis of Preparation
Basis of Preparation
The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and with the instructions to Article 10 of Securities and Exchange Commission Regulation S-X, as amended. They do not include all information and footnotes necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes contained in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2016. All significant intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (consisting of normal recurring adjustments and accruals) considered necessary for a fair presentation of the results of operations for the periods presented have been included in the interim periods. Operating results for the six months ended December 31, 2016 are not necessarily indicative of the results that may be expected for the fiscal year ending June 30, 2017. The condensed consolidated balance sheet at June 30, 2016 is derived from the audited financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended June 30, 2016.
Reclassification
Reclassification

The Company has reclassified certain amounts previously reported in its financial statements to conform to the current presentation. These reclassifications did not have a material impact on our consolidated financial statements.
Use of Estimates
Use of Estimates
The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires the Company to make estimates, judgments and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. To the extent there are material differences between these estimates and actual results, the Company's condensed consolidated financial statements will be affected. On an ongoing basis, the Company evaluates the estimates, judgments and assumptions including those related to stock rotation returns, price adjustments, allowance for doubtful accounts, inventory reserves, warranty accrual, income taxes, share-based compensation, and useful lives for property, plant and equipment and intangible assets.
Fair Value of Financial Instruments
Fair Value of Financial Instruments
The fair values of cash equivalents are based on observable market prices and have been categorized in Level 1 in the fair value hierarchy. Cash equivalents consist primarily of short term bank deposits. The carrying values of financial instruments such as cash and cash equivalents, accounts receivable and accounts payable approximate their carrying values due to their short-term maturities.
Impairment of Long-Lived Assets [Policy Text Block]
Impairment of Long-Lived Assets

Long-lived assets or asset groups are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset might not be recoverable. Factors that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or any other significant adverse change that would indicate that the carrying amount of an asset or group of assets may not be recoverable. Where such factors indicate potential impairment, the recoverability of an asset or asset group is assessed by determining if the carrying value of the asset or asset group exceeds the sum of the projected undiscounted cash flows expected to result from the use and eventual disposition of the assets over the remaining economic life.  The impairment loss is measured based on the difference between the carrying amount and the estimated fair value.
Comprehensive Income (Loss)
Comprehensive Income (Loss)
Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. The Company's accumulated other comprehensive income (loss) consists of cumulative foreign currency translation adjustments. Total comprehensive income (loss) is presented in the condensed consolidated statements of comprehensive income (loss).
Recent Accounting Pronouncements
Recent Accounting Pronouncements
    
In November 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-18, "Statement of Cash Flows: Restricted Cash ("ASU 2016-18"). ASU 2016-18 requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the total beginning and ending amounts for the periods shown on the statement of cash flows. This ASU will be effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted and requires retrospective adoption.  The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows.

In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory ("ASU 2016-16"). ASU 2016-16 requires entities to recognize income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The amended guidance is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods wihin annual periods beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact the adoption of ASU 2016-16 will have on its consolidated financial statements.

In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments ("ASU 2016-15"). ASU 2016-15 identifies how certain cash receipts and cash payments are presented and classified in the Statement of Cash Flows under Topic 230. ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, with early adoption permitted.  Upon adoption, entities must apply the guidance retrospectively to all periods presented. The Company is currently evaluating the impact the adoption of ASU 2016-15 will have on its consolidated financial statements.

In May 2016, the FASB issued Accounting Standards Update ("ASU") 2016-12, "Revenue from Contracts with Customers (Topic 606) - Narrow-Scope Improvements and Practical Expedients." ASU 2016-12 provides additional guidance established by the FASB-IASB Joint Transition Resource Group for Revenue Recognition regarding the implementation of certain aspects of the new revenue recognition guidance. More specifically, the amendment provides additional guidance regarding assessing the collectibility criterion, the presentation of sales taxes and other similar taxes collected from customers, noncash consideration, contract modifications or completed contracts at transition of the new revenue recognition guidance and technical corrections. The effective date is consistent with the effective date of ASU 2014-09. The Company is currently evaluating the impact the adoption of ASU 2016-12 will have on its consolidated financial statements. The Company does not plan to early adopt this standard.

In April 2016, the FASB issued ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10"). ASU 2016-10 clarifies two aspects of Topic 606: (a) identifying performance obligations; and (b) the licensing implementation guidance. The update is effective for annual periods beginning after December 15, 2017 including interim reporting periods therein. The Company is currently evaluating the impact the adoption of ASU 2016-10 will have on its consolidated financial statements.

In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 simplifies several aspects of the accounting for employee share-based payment transactions including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification of related amounts within the statement of cash flows. This guidance is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted. The Company does not expect the adoption of this guidance will have a material impact on its consolidated financial position, results of operations or cash flows.

In February 2016, the FASB issued No. 2016-02, Leases ("ASU 2016-02"). This guidance requires a dual approach for lessee accounting under which a lessee will account for leases as finance leases or operating leases. Both finance and operating leases will result in the lessee recognizing a right-of-use asset and a corresponding liability on its balance sheet, with differing methodology for income statement recognition. This guidance is effective for public business entities for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. A modified retrospective approach is required for all leases existing or entered into after the beginning of the earliest comparative period in the consolidated financial statements. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”). The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. In August 2015, the FASB issued an accounting standard update for a one-year deferral of the effective date of ASU 2014-09 to annual and interim periods beginning after December 15, 2017 and permits entities to early adopt the standard of ASU 2014-09 for annual and interim reporting periods beginning after December 15, 2016. Companies are permitted to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment.  The Company is in the process of evaluating the timing of its adoption and the impact of adoption on its consolidated financial statements.
Concentration of Credit Risk
The Company manages its credit risk associated with exposure to distributors and direct customers on outstanding accounts receivable through the application and review of credit approvals, credit ratings and other monitoring procedures. In some instances, the Company also obtains letters of credit from certain customers.
Credit sales, which are mainly on credit terms of 30 to 60 days, are only made to customers who meet the Company's credit requirements, while sales to new customers or customers with low credit ratings are usually made on an advance payment basis. The Company considers its trade accounts receivable to be of good credit quality because its key distributors and direct customers have long-standing business relationships with the Company and the Company has not experienced any significant write-offs of accounts receivable in the past. The Company closely monitors the aging of accounts receivable from its distributors and direct customers, and regularly reviews their financial positions, when available.
v3.6.0.2
Net Income (Loss) Per Share (Tables)
6 Months Ended
Dec. 31, 2016
Earnings Per Share [Abstract]  
Schedule of Earnings Per Share, Basic and Diluted
The following table presents the calculation of basic and diluted net income (loss) per share attributable to common shareholders:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands, except per share data)
Numerator:
 
 
 
 
 
 
 
Net income (loss) attributable to Alpha and Omega Semiconductor Limited
$
2,847

 
$
(1,611
)
 
$
6,154

 
$
(3,586
)
 
 
 
 
 
 
 
 
Denominator:
 
 
 
 
 
 
 
Basic:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income (loss) per share
23,481

 
22,269

 
23,256

 
22,483

Diluted:
 
 
 
 
 
 
 
Weighted average number of common shares used to compute basic net income (loss) per share
23,481

 
22,269

 
23,256

 
22,483

Effect of potentially dilutive securities:
 
 
 
 
 
 
 
Stock options, RSUs and ESPP shares
1,496

 

 
1,439

 

Weighted average number of common shares used to compute diluted net income (loss) per share
24,977

 
22,269

 
24,695

 
22,483

Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited:
 
 
 
 
 
 
 
Basic
$
0.12

 
$
(0.07
)
 
$
0.26

 
$
(0.16
)
Diluted
$
0.11

 
$
(0.07
)
 
$
0.25

 
$
(0.16
)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share
The following potential dilutive securities were excluded from the computation of diluted net income (loss) per share as their effect would have been anti-dilutive:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Employee stock options and RSUs

 
3,299

 
123

 
3,458

ESPP
16

 
551

 
8

 
369

Total potential dilutive securities
16

 
3,850

 
131

 
3,827

v3.6.0.2
Concentration of Credit Risk and Significant Customers (Tables)
6 Months Ended
Dec. 31, 2016
Risks and Uncertainties [Abstract]  
Schedules of Concentration of Risk, by Risk Factor
Summarized below are individual customers whose revenue or accounts receivable balances were more than 10% of the respective total consolidated amounts:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
Percentage of revenue
2016
 
2015
 
2016
 
2015
Customer A
27.0
%
 
24.0
%
 
25.6
%
 
23.6
%
Customer B
35.8
%
 
39.6
%
 
36.2
%
 
37.8
%
Customer C
10.7
%
 
10.8
%
 
12.3
%
 
12.6
%

 
December 31,
2016
 
June 30,
2016
Percentage of accounts receivable
 
Customer A
35.8
%
 
21.3
%
Customer B
9.6
%
 
16.7
%
Customer C
24.7
%
 
27.2
%
v3.6.0.2
Balance Sheet Components (Tables)
6 Months Ended
Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]  
Schedule of Accounts, Notes, Loans and Financing Receivable
Accounts receivable:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Accounts receivable
$
42,109

 
$
43,324

Less: Allowance for price adjustments
(17,597
)
 
(16,700
)
Less: Allowance for doubtful accounts
(30
)
 
(30
)
Accounts receivable, net
$
24,482

 
$
26,594

Schedule of Inventory, Current
Inventories:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Raw materials
$
25,622

 
$
23,982

Work in-process
34,369

 
32,446

Finished goods
10,248

 
12,420

 
$
70,239

 
$
68,848

Property, Plant and Equipment
Property, plant and equipment, net:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Land
$
4,877

 
$
4,877

Building
4,325

 
4,323

Manufacturing machinery and equipment
201,425

 
193,164

Equipment and tooling
13,185

 
12,289

Computer equipment and software
23,921

 
23,448

Office furniture and equipment
1,943

 
1,822

Leasehold improvements
28,896

 
28,660

 
278,572

 
268,583

Less: Accumulated depreciation
(179,760
)
 
(168,687
)
 
98,812

 
99,896

Equipment and construction in progress
23,874

 
16,188

Property, plant and equipment, net
$
122,686

 
$
116,084

Schedule of Other Assets, Noncurrent
Other long-term assets:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Prepayments for property and equipment
$
2,087

 
$
506

Prepayment for others
226

 
42

Prepaid income tax
4,998

 

Investment in a privately held company
100

 
100

Office leases deposits
2,546

 
1,427

Intangible assets
14

 
15

Goodwill
269

 
269

 
$
10,240

 
$
2,359

Schedule of Accrued Liabilities
Accrued liabilities:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Accrued compensation and benefit
$
13,457

 
$
10,211

Warranty accrual
2,382

 
1,495

Stock rotation accrual
1,707

 
1,988

Accrued professional fees
1,741

 
1,867

Accrued inventory
448

 
918

Accrued facilities related expenses
1,269

 
1,544

Other accrued expenses
4,095

 
4,567

 
$
25,099

 
$
22,590

Schedule of Product Warranty Liability
The activities in the warranty accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2016
 
2015
 
(in thousands)
Beginning balance
$
1,495

 
$
1,957

Additions
1,040

 
747

Utilization
(153
)
 
(1,108
)
Ending balance
$
2,382

 
$
1,596

Stock Rotation Accrual
The activities in the stock rotation accrual, included in accrued liabilities, are as follows:
 
Six Months Ended December 31,
 
2016
 
2015
 
(in thousands)
Beginning balance
$
1,988

 
$
1,894

Additions
3,008

 
3,120

Utilization
(3,289
)
 
(3,142
)
Ending balance
$
1,707

 
$
1,872

Schedule of Other Noncurrent Liabilities
Other Long-term liabilities:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
Deferred rent
$
623

 
$
741

v3.6.0.2
Joint Venture (Tables)
6 Months Ended
Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]  
Schedule of Stockholders Equity
The changes in total stockholders' equity and noncontrolling interest were as follows (in thousands):

 
 
Total AOS Stockholders' Equity
 
Noncontrolling Interest
 
Total Equity
Balance, June 30, 2016
 
$
242,142

 
$
(103
)
 
$
242,039

     Contributions from noncontrolling interest
 

 
33,000

 
33,000

Exercise of common stock options and release of RSUs
 
7,239

 

 
7,239

Issuance of shares under ESPP
 
1,166

 

 
1,166

Reissuance of treasury stock upon exercise of common stock options and release of RSUs
 
324

 

 
324

Withholding tax on restricted stock units
 
(348
)
 

 
(348
)
     Stock-based compensation expense
 
2,870

 

 
2,870

      Net income (loss)
 
6,154

 
(2,067
)
 
4,087

     Cumulative translation adjustment
 
(1,191
)
 
(1,065
)
 
(2,256
)
Balance, December 31, 2016
 
$
258,356

 
$
29,765

 
$
288,121

v3.6.0.2
Shareholders' Equity and Share-based Compensation (Tables)
6 Months Ended
Dec. 31, 2016
Share-based Compensation [Abstract]  
Summary of Stock Option Activities
Stock Options
The Company did not grant any stock options during the six months ended December 31, 2016. Options expected to vest are the result of applying the pre-vesting forfeiture rate assumption to total outstanding options.
The following table summarizes the Company's stock option activities for the six months ended December 31, 2016:
 
 
 
 
 
Weighted
 
 
 
 
 
Weighted
 
Average
 
 
 
 
 
Average
 
Remaining
 
 
 
Number of
 
Exercise Price
 
Contractual
 
Aggregate
 
Shares
 
Per Share
 
Term (in years)
 
Intrinsic Value
Outstanding at June 30, 2016
1,859,260

 
$
11.37

 
4.71
 
$
5,959,720

Granted

 
$

 
 
 
 
Exercised
(637,406
)
 
$
11.87

 
 
 
$
5,189,023

Canceled or forfeited
(90,000
)
 
$
12.63

 
 
 
 
Outstanding at December 31, 2016
1,131,854

 
$
11.00

 
4.93
 
$
11,625,154

Options vested and expected to vest
1,121,561

 
$
11.03

 
4.91
 
$
11,484,305

Exercisable at December 31, 2016
951,973

 
$
11.65

 
4.50
 
$
9,162,612


Restricted Stock Units Activity
Restricted Stock Units ("RSU")
The following table summarizes the Company's RSU activities for the six months ended December 31, 2016:
 
Number of Restricted Stock
Units
 
Weighted Average
Grant Date Fair
Value Per Share
 
Weighted Average
Remaining
Recognition
Period (Years)
 
Aggregate Intrinsic Value
Nonvested at June 30, 2016
933,063

 
$
9.18

 
1.73
 
$
12,997,568

Granted
109,617

 
$
20.18

 
 
 
 
Vested
(78,235
)
 
$
9.40

 
 
 
 
Forfeited
(18,725
)
 
$
10.94

 
 
 
 
Nonvested at December 31, 2016
945,720

 
$
10.40

 
1.40
 
$
20,115,464

RSUs vested and expected to vest
829,631

 
 
 
1.30
 
$
17,646,257

The fair value of RSU is estimated based on the market price of the Company's share on the date of grant.
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]
Employee Share Purchase Plan ("ESPP")
The assumptions used to estimate the fair values of common shares issued under the ESPP were as follows:
 
 
 
Six Months Ended December 31,
 
2016
Volatility rate
39.09%
Risk-free interest rate
0.6% - 1.0%
Expected term
1.3 years
Dividend yield
0%
Share-based Compensation, Allocation of Recognized Period Costs
Share-based Compensation Expense
The total share-based compensation expense related to stock options, RSUs and ESPP described above, recognized in the condensed consolidated statements of operations for the periods presented was as follows:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Cost of goods sold
$
205

 
$
157

 
$
400

 
$
288

Research and development
383

 
264

 
743

 
457

Selling, general and administrative
966

 
664

 
1,727

 
1,129

 
$
1,554

 
$
1,085

 
$
2,870

 
$
1,874

v3.6.0.2
Segment and Geographic Information (Tables)
6 Months Ended
Dec. 31, 2016
Segment Reporting [Abstract]  
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas
Long-lived assets, net consisting of property, plant and equipment, by geographical area are as follows:
 
December 31,
2016
 
June 30,
2016
 
(in thousands)
China
$
68,639

 
$
64,272

United States
53,432

 
51,214

Other Countries
615

 
598

 
$
122,686

 
$
116,084

The revenue by geographical location in the following tables is based on the country or region to which the products were shipped to:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Hong Kong
$
78,253

 
$
69,904

 
$
161,088

 
$
140,357

China
14,383

 
7,922

 
26,825

 
16,938

South Korea
393

 
442

 
759

 
1,100

United States
798

 
784

 
1,692

 
1,501

Other Countries
860

 
773

 
1,685

 
1,368

 
$
94,687

 
$
79,825

 
$
192,049

 
$
161,264

Revenue from External Customers by Products and Services
The following is a summary of revenue by product type:
 
Three Months Ended December 31,
 
Six Months Ended December 31,
 
2016
 
2015
 
2016
 
2015
 
(in thousands)
 
(in thousands)
Power discrete
$
69,822

 
$
59,392

 
$
141,250

 
$
119,305

Power IC
21,859

 
16,400

 
44,857

 
33,913

Packaging and testing services
3,006

 
4,033

 
5,942

 
8,046

 
$
94,687

 
$
79,825

 
$
192,049

 
$
161,264

v3.6.0.2
The Company and Significant Accounting Policies Joint Venture (Details) - Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member] - USD ($)
$ in Millions
1 Months Ended
Mar. 31, 2016
Mar. 29, 2016
Corporate Joint Venture [Member]    
Initial capitalization of joint venture   $ 330.0
Chongqing Funds [Member]    
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions 49.00%  
Parent Company [Member]    
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions 51.00%  
v3.6.0.2
Net Income (Loss) Per Share - Basic and Diluted Income Per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Numerator:        
Net income (loss) attributable to Alpha and Omega Semiconductor Limited $ 2,847 $ (1,611) $ 6,154 $ (3,586)
Basic:        
Weighted average number of common shares used to compute basic net income (loss) per share 23,481 22,269 23,256 22,483
Effect of potentially dilutive securities:        
Stock options, RSUs and ESPP shares 1,496 0 1,439 0
Weighted average number of common shares used to compute diluted net income (loss) per share 24,977 22,269 24,695 22,483
Net income (loss) per share attributable to Alpha and Omega Semiconductor Limited:        
Basic (in dollars per share) $ 0.12 $ (0.07) $ 0.26 $ (0.16)
Diluted (in dollars per share) $ 0.11 $ (0.07) $ 0.25 $ (0.16)
v3.6.0.2
Net Income (Loss) Per Share - Potential Dilutive Shares (Details) - shares
shares in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Potential dilutive securities (in shares) 16 3,850 131 3,827
Employee stock options and RSUs        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Potential dilutive securities (in shares) 0 3,299 123 3,458
ESPP        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Potential dilutive securities (in shares) 16 551 8 369
v3.6.0.2
Concentration of Credit Risk and Significant Customers - (Details)
3 Months Ended 6 Months Ended
Dec. 31, 2016
Jun. 30, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Minimum [Member]          
Concentration Risk          
Terms of credit sales, (in days)       30 days  
Maximum [Member]          
Concentration Risk          
Terms of credit sales, (in days)       60 days  
Customer A | Sales Revenue, Goods, Net | Customer Concentration Risk          
Concentration Risk          
Customers greater than 10% of total 27.00%   24.00% 25.60% 23.60%
Customer A | Accounts Receivable | Customer Concentration Risk          
Concentration Risk          
Customers greater than 10% of total 35.80% 21.30%      
Customer B | Sales Revenue, Goods, Net | Customer Concentration Risk          
Concentration Risk          
Customers greater than 10% of total 35.80%   39.60% 36.20% 37.80%
Customer B | Accounts Receivable | Customer Concentration Risk          
Concentration Risk          
Customers greater than 10% of total 9.60% 16.70%      
Customer C | Sales Revenue, Goods, Net | Customer Concentration Risk          
Concentration Risk          
Customers greater than 10% of total 10.70%   10.80% 12.30% 12.60%
Customer C | Accounts Receivable | Customer Concentration Risk          
Concentration Risk          
Customers greater than 10% of total 24.70% 27.20%      
v3.6.0.2
Balance Sheet Components - Accounts receivable (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]    
Accounts receivable $ 42,109 $ 43,324
Less: Allowance for price adjustments (17,597) (16,700)
Less: Allowance for doubtful accounts (30) (30)
Accounts receivable, net $ 24,482 $ 26,594
v3.6.0.2
Balance Sheet Components - Inventories (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]    
Raw materials $ 25,622 $ 23,982
Work in-process 34,369 32,446
Finished goods 10,248 12,420
Inventory, net $ 70,239 $ 68,848
v3.6.0.2
Balance Sheet Components - Property, plant, and equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross $ 278,572 $ 268,583
Less: Accumulated depreciation (179,760) (168,687)
Property, plant and equipment excluding equipment and construction in progress, net 98,812 99,896
Equipment and construction in progress 23,874 16,188
Property, plant and equipment, net 122,686 116,084
Land    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross 4,877 4,877
Building    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross 4,325 4,323
Manufacturing machinery and equipment    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross 201,425 193,164
Equipment and tooling    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross 13,185 12,289
Computer equipment and software    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross 23,921 23,448
Office furniture and equipment    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross 1,943 1,822
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Property, plant, and equipment excluding equipment and construction In progress, gross $ 28,896 $ 28,660
v3.6.0.2
Balance Sheet Components - Other long term assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]    
Prepayments for property and equipment $ 2,087 $ 506
Prepayment for others 226 42
Prepaid income tax 4,998 0
Investment in a privately held company 100 100
Office leases deposits 2,546 1,427
Intangible assets 14 15
Goodwill 269 269
Other long-term assets $ 10,240 $ 2,359
v3.6.0.2
Balance Sheet Components - Accrued liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Dec. 31, 2015
Jun. 30, 2015
Balance Sheet Related Disclosures [Abstract]        
Accrued compensation and benefit $ 13,457 $ 10,211    
Warranty accrual 2,382 1,495 $ 1,596 $ 1,957
Stock rotation accrual 1,707 1,988 $ 1,872 $ 1,894
Accrued professional fees 1,741 1,867    
Accrued inventory 448 918    
Accrued facilities related expenses 1,269 1,544    
Other accrued expenses 4,095 4,567    
Accrued liabilities $ 25,099 $ 22,590    
v3.6.0.2
Balance Sheet Components - Product Warranty Accrual (Details) - USD ($)
$ in Thousands
6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]    
Beginning balance $ 1,495 $ 1,957
Additions 1,040 747
Utilization (153) (1,108)
Ending balance $ 2,382 $ 1,596
v3.6.0.2
Balance Sheet Components - Stock Rotation Accrual (Details) - USD ($)
$ in Thousands
6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Stock Rotation Accrual Increae (Decrease) [Roll Forward]    
Beginning balance $ 1,988 $ 1,894
Additions 3,008 3,120
Utilization (3,289) (3,142)
Ending balance $ 1,707 $ 1,872
v3.6.0.2
Balance Sheet Components - Other Long Term Liability (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Balance Sheet Related Disclosures [Abstract]    
Deferred rent $ 623 $ 741
Other long term liabilities $ 623 $ 741
v3.6.0.2
Joint Venture - Narrative (Details)
1 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2016
Sep. 30, 2016
USD ($)
Jun. 30, 2017
USD ($)
Jan. 10, 2017
CNY (¥)
Jan. 10, 2017
USD ($)
Mar. 29, 2016
USD ($)
Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]            
Schedule of Equity Method Investments [Line Items]            
Interest rate to concontrolling interest if joint venture is early terminated and liquidated 10.00%          
Corporate Joint Venture [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]            
Schedule of Equity Method Investments [Line Items]            
Initial capitalization of joint venture           $ 330,000,000
Parent Company [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]            
Schedule of Equity Method Investments [Line Items]            
Percent ownership in joint venture 51.00%          
Chongqing Funds [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]            
Schedule of Equity Method Investments [Line Items]            
Percent ownership in joint venture 49.00%          
Payments to acquire interest in joint venture   $ 33,000,000        
Scenario, Forecast [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]            
Schedule of Equity Method Investments [Line Items]            
Consideration transferred to acquire interest in joint venture     $ 10,000,000      
Subsequent Event [Member] | Corporate Joint Venture [Member]            
Schedule of Equity Method Investments [Line Items]            
Total price payable under EPC Contract       ¥ 540,000,000 $ 77,996,360  
Contract amount payable in 2017         58,300,000  
Contract amount payable in 2018         19,700,000  
Design Fees [Member] | Subsequent Event [Member] | Corporate Joint Venture [Member]            
Schedule of Equity Method Investments [Line Items]            
Total price payable under EPC Contract       19,525,052 2,820,154  
Construction and Procurement Fees [Member] | Subsequent Event [Member] | Corporate Joint Venture [Member]            
Schedule of Equity Method Investments [Line Items]            
Total price payable under EPC Contract       ¥ 520,474,948 $ 75,176,206  
v3.6.0.2
Joint Venture - Changes in Total Stockholders' Equity (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Balance, June 30, 2016     $ 242,039  
Contributions from noncontrolling interest     33,000  
Exercise of common stock options and release of RSUs     7,239  
Issuance of shares under ESPP     1,166  
Reissuance of treasury stock upon exercise of common stock options and release of RSUs     324  
Withholding tax on restricted stock units     (348)  
Stock-based compensation expense     2,870  
Net income (loss) $ 1,657 $ (1,611) 4,087 $ (3,586)
Net loss attributable to noncontrolling interest (1,190) $ 0 (2,067) $ 0
Cumulative translation adjustment     (2,256)  
Ending balance 288,121   288,121  
Parent [Member]        
Balance, June 30, 2016     242,142  
Contributions from noncontrolling interest     0  
Exercise of common stock options and release of RSUs     7,239  
Issuance of shares under ESPP     1,166  
Reissuance of treasury stock upon exercise of common stock options and release of RSUs     324  
Withholding tax on restricted stock units     (348)  
Stock-based compensation expense     2,870  
Net income (loss)     6,154  
Cumulative translation adjustment     (1,191)  
Ending balance 258,356   258,356  
Noncontrolling Interest [Member]        
Balance, June 30, 2016     (103)  
Contributions from noncontrolling interest     33,000  
Exercise of common stock options and release of RSUs     0  
Issuance of shares under ESPP     0  
Reissuance of treasury stock upon exercise of common stock options and release of RSUs     0  
Withholding tax on restricted stock units     0  
Stock-based compensation expense     0  
Cumulative translation adjustment     (1,065)  
Ending balance $ 29,765   $ 29,765  
v3.6.0.2
Shareholders' Equity and Share-based Compensation - Shares Repurchase (Details) - USD ($)
$ / shares in Units, $ in Millions
6 Months Ended 74 Months Ended
Jul. 07, 2015
Dec. 31, 2016
Dec. 31, 2016
Jan. 31, 2017
Jun. 07, 2015
Apr. 30, 2015
Mar. 31, 2015
Class of Stock [Line Items]              
Shares Repurchase Program Remaining Balance   $ 6.4 $ 6.4     $ 50.0 $ 17.8
Treasury Stock, Shares, Acquired   0 5,723,093        
Treasury Stock, Value, Acquired, Cost Method     $ 50.8        
Treasury stock acquired, average price per share (in dollars per share)     $ 8.87        
Treasury Stock, Shares, Retired     0        
Treasury Stock Reissued, Average Price Per Share     $ 6.13        
Treasury Stock Reissued              
Class of Stock [Line Items]              
Treasury stock acquired, average price per share (in dollars per share)     $ 11.17        
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures (in shares)     103,003        
Dutch Auction Tender Offer [Member] | Common Stock [Member]              
Class of Stock [Line Items]              
Share repurchase program, authorized amount (USD in Millions)         $ 30.0    
Treasury Stock, Shares, Acquired 3,296,703            
Treasury stock acquired, average price per share (in dollars per share) $ 9.10            
Subsequent Event [Member]              
Class of Stock [Line Items]              
Aggregate offer price authorized under the Shelf Registration Statement       $ 250.0      
v3.6.0.2
Shareholders' Equity and Share-based Compensation - Share-based Compensation (Details) - USD ($)
3 Months Ended 6 Months Ended 74 Months Ended
Dec. 31, 2016
Jun. 30, 2016
Dec. 31, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Treasury Stock, Shares, Acquired     0 5,723,093
Options, Weighted-Average Remaining Contractual Life (in years)   4 years 8 months 16 days 4 years 11 months 5 days  
Options vested and expected to vest, Number Outstanding (in shares) 1,121,561   1,121,561 1,121,561
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share) $ 11.03   $ 11.03 $ 11.03
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)     4 years 10 months 28 days  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value $ 11,484,305   $ 11,484,305 $ 11,484,305
Options, Number Exercisable (in shares) 951,973   951,973 951,973
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price $ 11.65   $ 11.65 $ 11.65
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term 4 years 6 months      
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value $ 9,162,612   $ 9,162,612 $ 9,162,612
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]        
Outstanding at June 30, 2016     1,859,260  
Granted (in shares)     0  
Exercised (in shares)     (637,406)  
Canceled or forfeited (in shares)     (90,000)  
Outstanding at December 31, 2016 1,131,854 1,859,260 1,131,854 1,131,854
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]        
Outstanding at June 30, 2016 (in dollars per share)     $ 11.37  
Granted (in dollars per share)     0  
Exercised (in dollars per share)     11.87  
Canceled or forfeited (in dollars per share)     12.63  
Outstanding at December 31, 2016 (in dollars per share) $ 11.00 $ 11.37 $ 11.00 $ 11.00
Options Outstanding Aggregate Intrinsic Value $ 11,625,154 $ 5,959,720 $ 11,625,154 $ 11,625,154
Options Exercised Aggregate Intrinsic Value     $ 5,189,023  
Employee Share Purchase Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Volatility Rate     39.09%  
Expected Term     1 year 3 months 18 days  
Expected Dividend Rate     0.00%  
Employee Share Purchase Plan [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Risk Free Interest Rate     0.60%  
Employee Share Purchase Plan [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Risk Free Interest Rate     1.00%  
v3.6.0.2
Shareholders' Equity and Share-based Compensation - Stock Options Outstanding and Exercisable (Details) - $ / shares
3 Months Ended 6 Months Ended
Jun. 30, 2016
Dec. 31, 2016
Share-based Compensation [Abstract]    
Options, Number Outstanding (in shares) 1,859,260 1,131,854
Options, Weighted-Average Remaining Contractual Life (in years) 4 years 8 months 16 days 4 years 11 months 5 days
Options, Weighted-Average Exercise Price (in dollars per share) $ 11.37 $ 11.00
Options, Number Exercisable (in shares)   951,973
Options, Weighted-Average Exercise Price (in dollars per share)   $ 11.65
Options vested and expected to vest, Number Outstanding (in shares)   1,121,561
Options vested and expected to vest, Weighted Average Remaining Contractual Life (in years)   4 years 10 months 28 days
Options vested and expected to vest, Weighted Average Exercise Price (in dollars per share)   $ 11.03
v3.6.0.2
Shareholders' Equity and Share-based Compensation - Restricted Stock Activity (Details) - USD ($)
3 Months Ended 6 Months Ended
Dec. 31, 2016
Jun. 30, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Weighted Average Remaining Recognition Period (Years) 1 year 3 months 18 days    
Restricted Stock      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Nonvested at June 30, 2016     933,063
Granted     109,617
Vested     (78,235)
Forfeited     (18,725)
Nonvested at December 31, 2016 945,720 933,063 945,720
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Nonvested at June 30, 2016     $ 9.18
Granted     20.18
Vested     9.40
Forfeited     10.94
Nonvested at December 31, 2016 $ 10.40 $ 9.18 $ 10.40
Weighted Average Remaining Recognition Period (Years) 1 year 4 months 24 days 1 year 8 months 23 days  
RSUs Nonvested Aggregate Intrinsic Value $ 20,115,464 $ 12,997,568 $ 20,115,464
RSUs vested and expected to vest, Outstanding (in shares) 829,631   829,631
RSUs vested and expected to vest, Weighted Average Remaining Recognition Period (in years) 1 year 3 months 18 days    
RSUs vested and expected to vest, Aggregate Intrinsic Value $ 17,646,257   $ 17,646,257
v3.6.0.2
Shareholders' Equity and Share-based Compensation - Share-based Compensation Expenses (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Allocated share-based compensation expense $ 1,554 $ 1,085 $ 2,870 $ 1,874
Unrecognized compensation expense $ 5,400   5,400  
Recognition period of share-based compensation expense (in years) 1 year 3 months 18 days      
Cost of goods sold        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Allocated share-based compensation expense $ 205 157 400 288
Research and development        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Allocated share-based compensation expense 383 264 743 457
Selling, general and administrative        
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]        
Allocated share-based compensation expense $ 966 $ 664 $ 1,727 $ 1,129
v3.6.0.2
Income Taxes - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Jun. 30, 2016
Related Party Transaction [Line Items]            
Income tax expense $ 1,085   $ 1,015 $ 2,322 $ 2,229  
Estimated effective income tax rate 39.60%   (170.30%) 36.20% (164.30%)  
Increase in deferred tax assets and prepaid tax asset   $ 6,600        
Prepaid taxes, current and noncurrent $ 6,100     $ 6,100    
Prepaid taxes, current 1,100     1,100    
Prepaid taxes, noncurrent 4,998     4,998   $ 0
Unrecognized tax benefits 6,900     6,900    
Unrecognized tax benefit that would impact effective tax rate $ 4,500     $ 4,500    
v3.6.0.2
Segment and Geographic Information - Revenue by Location and Product Type (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue $ 94,687 $ 79,825 $ 192,049 $ 161,264
Power discrete        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 69,822 59,392 141,250 119,305
Power IC        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 21,859 16,400 44,857 33,913
Packaging and testing services        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 3,006 4,033 5,942 8,046
Hong Kong        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 78,253 69,904 161,088 140,357
China        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 14,383 7,922 26,825 16,938
South Korea        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 393 442 759 1,100
United States        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue 798 784 1,692 1,501
Other Countries        
Revenues from External Customers and Long-Lived Assets [Line Items]        
Revenue $ 860 $ 773 $ 1,685 $ 1,368
v3.6.0.2
Segment and Geographic Information - Long-lived Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Jun. 30, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]    
Property, plant and equipment, net $ 122,686 $ 116,084
China    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Property, plant and equipment, net 68,639 64,272
United States    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Property, plant and equipment, net 53,432 51,214
Other Countries    
Revenues from External Customers and Long-Lived Assets [Line Items]    
Property, plant and equipment, net $ 615 $ 598
v3.6.0.2
Segment and Geographic Information - Narratives (Details)
6 Months Ended
Dec. 31, 2016
Segment
Segment Reporting [Abstract]  
Number of operating segments 1
Number of reportable segments 1
v3.6.0.2
Commitments and Contingencies - Purchase Commitments (Details) - USD ($)
$ in Millions
Dec. 31, 2016
Jun. 30, 2016
Raw materials, wafers, and packaging and testing services puchase commitments    
Purchase Commitment, Excluding Long-term Committment [Line Items]    
Purchase commitment, amount $ 25.9 $ 39.6
Property and equipment purchase commitments    
Purchase Commitment, Excluding Long-term Committment [Line Items]    
Purchase commitment, amount $ 10.3 $ 6.6
v3.6.0.2
Commitments and Contingencies - Guarantees (Details) - USD ($)
Dec. 31, 2016
Jun. 30, 2016
Indemnification Agreement    
Loss Contingencies [Line Items]    
Indemnifications accrual $ 0 $ 0
v3.6.0.2
Commitments and Contingencies - Other Investments (Details)
1 Months Ended 12 Months Ended
Mar. 31, 2016
Jun. 30, 2017
USD ($)
Jan. 10, 2017
CNY (¥)
Jan. 10, 2017
USD ($)
Mar. 29, 2016
USD ($)
Corporate Joint Venture [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Initial capitalization of joint venture         $ 330,000,000
Parent Company [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions 51.00%        
Chongqing Funds [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions 49.00%        
Scenario, Forecast [Member] | Facility in Liangjiang New Area of Chongqing (the 'Joint Venture') [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Consideration transferred to acquire interest in joint venture   $ 10,000,000      
Subsequent Event [Member] | Corporate Joint Venture [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Total price payable under EPC Contract     ¥ 540,000,000 $ 77,996,360  
Design Fees [Member] | Subsequent Event [Member] | Corporate Joint Venture [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Total price payable under EPC Contract     19,525,052 2,820,154  
Construction and Procurement Fees [Member] | Subsequent Event [Member] | Corporate Joint Venture [Member]          
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]          
Total price payable under EPC Contract     ¥ 520,474,948 $ 75,176,206