Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2018	Jul. 19, 2018
Document Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Trading Symbol	NVCR
Entity Registrant Name	Novocure Ltd
Entity Central Index Key	0001645113
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		92,902,560

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 114,456	$ 78,592
Short-term investments	104,499	104,719
Restricted cash	2,169	2,126
Trade receivables	37,643	29,567
Receivables and prepaid expenses	11,216	8,105
Inventories	19,906	22,025
Total current assets	289,889	245,134
LONG-TERM ASSETS:
Property and equipment, net	8,891	9,031
Field equipment, net	8,108	9,036
Severance pay fund	111	111
Other long-term assets	2,877	1,986
Total long-term assets	19,987	20,164
TOTAL ASSETS	309,876	265,298
CURRENT LIABILITIES:
Trade payables	20,434	17,206
Other payables and accrued expenses	24,813	32,996
Total current liabilities	45,247	50,202
LONG-TERM LIABILITIES:
Long-term loan, net of discount and issuance costs	149,195	97,342
Employee benefit liabilities	2,473	2,453
Other long-term liabilities	880	1,737
Total long-term liabilities	152,548	101,532
TOTAL LIABILITIES	197,795	151,734
COMMITMENTS AND CONTINGENCIES	0	0
SHAREHOLDERS' EQUITY:
Ordinary shares no par value, unlimited shares authorized; issued and outstanding: 92,503,273 shares and 89,478,032 shares at June 30, 2018 (unaudited) and December 31, 2017, respectively	0	0
Additional paid-in capital	729,684	697,165
Accumulated other comprehensive loss	(1,273)	(1,343)
Accumulated deficit	(616,330)	(582,258)
Total shareholders' equity	112,081	113,564
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 309,876	$ 265,298

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Common stock, par value
Common stock, shares authorized	Unlimited	Unlimited
Common stock, shares issued	92,503,273	89,478,032
Common stock, shares outstanding	92,503,273	89,478,032

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Statement [Abstract]
Net revenues	$ 61,514	$ 38,376	$ 113,639	$ 73,256	$ 177,026
Cost of revenues	19,833	13,152	38,071	24,816	55,609
Gross profit	41,681	25,224	75,568	48,440	121,417
Operating costs and expenses:
Research, development and clinical trials	11,362	9,371	22,466	18,782	38,103
Sales and marketing	19,196	16,360	37,331	31,116	63,528
General and administrative	18,208	15,023	35,533	27,445	59,114
Total operating costs and expenses	48,766	40,754	95,330	77,343	160,745
Operating loss	(7,085)	(15,530)	(19,762)	(28,903)	(39,328)
Financial expenses, net	2,860	2,183	7,713	4,629	9,169
Loss before income taxes	(9,945)	(17,713)	(27,475)	(33,532)	(48,497)
Income taxes	5,565	3,461	8,759	5,687	13,165
Net loss	$ (15,510)	$ (21,174)	$ (36,234)	$ (39,219)	$ (61,662)
Basic and diluted net loss per ordinary share	$ (0.17)	$ (0.24)	$ (0.40)	$ (0.45)	$ (0.70)
Weighted average number of ordinary shares used in computing basic and diluted net loss per share	91,331,862	88,218,868	90,658,735	87,835,926	88,546,719

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (15,510)	$ (21,174)	$ (36,234)	$ (39,219)	$ (61,662)
Other comprehensive income (loss), net of tax:
Change in foreign currency translation adjustments	11	1	21	10	8
Pension benefit plan	44	183	49	134	532
Total comprehensive loss	$ (15,455)	$ (20,990)	$ (36,164)	$ (39,075)	$ (61,122)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - 6 months ended Jun. 30, 2018 - USD ($)
$ in Thousands

Total

Ordinary Shares

Additional Paid-in Capital

Accumulated Other Comprehensive Loss

Accumulated Deficit

Balance at Dec. 31, 2017

$ 113,564

$ 697,165

$ (1,343)

$ (582,258)

Balance (in shares) at Dec. 31, 2017

89,478,032

Proceeds from issuance of shares

938

Proceeds from issuance of shares (in shares)

54,386

Share-based compensation to employees

18,726

Exercise of options and warrants and vested RSUs

12,855

Exercise of options and warrants and vested RSUs (in shares)

2,970,855

Cumulative effect adjustment on retained earnings

^[1]

2,162

Other comprehensive income, net of tax benefit of $8

70

Net loss

(36,234)

Balance at Jun. 30, 2018

$ 112,081

$ 729,684

$ (1,273)

$ (616,330)

Balance (in shares) at Jun. 30, 2018

92,503,273

[1]	Resulting from the adoption of ASC 606.

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Statement Of Stockholders Equity [Abstract]
Other comprehensive income (loss), tax benefit	$ 8

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (15,510)	$ (21,174)	$ (36,234)	$ (39,219)	$ (61,662)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,287	1,811	4,490	3,471	7,677
Asset write-downs and impairment of field equipment	93	59	142	134	241
Share-based compensation to employees	10,206	7,570	18,726	12,131	27,116
Increase in trade receivables	(3,599)	(2,064)	(5,271)	(7,550)	(23,228)
Amortization of discount	(370)	103	2,057	209	252
Decrease (increase) in receivables and prepaid expenses	(1,277)	3,354	(3,111)	(1,461)	1,979
Decrease in inventories	482	803	2,120	403	3,524
Increase in other long-term assets	(278)	(38)	(898)	(294)	(554)
Increase (decrease) in trade payables	1,016	(1,638)	3,229	(5,195)	(1,150)
Increase (decrease) in other payables and accrued expenses	(528)	4,888	(8,828)	3,478	14,460
Increase in employee benefit liabilities, net	1	130	77	239	440
Increase (decrease) in other long-term liabilities	(16)	321	(816)	870	(2,229)
Net cash used in operating activities	(7,493)	(5,875)	(24,317)	(32,784)	(33,134)
Cash flows from investing activities:
Purchase of property and equipment	(854)	(376)	(1,591)	(1,406)	(2,459)
Purchase of field equipment	(604)	(859)	(1,974)	(2,261)	(4,907)
Proceeds from maturity of short-term investments	60,000	60,000	105,000	120,000	120,000
Purchase of short-term investments	(59,384)	(59,352)	(104,134)	(104,006)	(104,006)
Net cash provided by (used in) investing activities	(842)	(587)	(2,699)	12,327	8,628
Cash flows from financing activities:
Proceeds from issuance of shares, net	938	781	938	781	1,540
Proceeds from long-term loan, net			149,150
Proceeds from other long-term loans		19		19	19
Repayment of long-term loan			(100,000)
Repayment of other long-term loan	(24)	(19)	(41)	(37)	(76)
Exercise of options and warrants	10,274	1,286	12,855	1,363	3,685
Net cash provided by financing activities	11,188	2,067	62,902	2,126	5,168
Effect of exchange rate changes on cash and cash equivalents	11	(1)	21	10	8
Increase (decrease) in cash, cash equivalents and restricted cash	2,864	(4,396)	35,907	(18,321)	(19,330)
Cash, cash equivalents and restricted cash at beginning of period	113,761	86,123	80,718	100,048	100,048
Cash, cash equivalents and restricted cash at the end of the period	116,625	81,727	116,625	81,727	80,718
Cash paid during the period for:
Income taxes	8,256	1,500	12,014	4,902	10,286
Interest	$ 3,416	$ 2,533	$ 6,425	$ 5,041	$ 10,162

Organization and Basis of Presentation	6 Months Ended
Organization and Basis of Presentation	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	NOTE 1: ORGANIZATION AND BASIS OF PRESENTATION Organization. NovoCure Limited (including its consolidated subsidiaries, the “Company”) was incorporated in the Bailiwick of Jersey and is principally engaged in the development, manufacture and commercialization of Tumor Treating Fields for the treatment of solid tumors. The Company has regulatory approvals and clearances in certain countries for Optune, its first Tumor Treating Fields delivery system, to treat adult patients with glioblastoma (“GBM”). Financial statement preparation. The accompanying consolidated financial statements include the accounts of the Company and its consolidated subsidiaries, and intercompany accounts and transactions have been eliminated. In the opinion of the Company’s management, the consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. The preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. These consolidated financial statements and accompanying notes should be read in conjunction with the Company’s annual consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017 (the “2017 10-K”) filed with the Securities and Exchange Commission (the “SEC”) on February 22, 2018. The significant accounting policies applied in the audited annual consolidated financial statements of the Company as disclosed in the 2017 10-K are applied consistently in these unaudited interim consolidated financial statements, except as noted below: Recently Adopted Accounting Pronouncements. In May 2014, FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09), an updated standard on revenue recognition and issued subsequent amendments to the initial guidance in March 2016, April 2016, May 2016 and December 2016 within ASU 2016-08, 2016-10, 2016-12 and 2016-20, respectively (collectively, “ASC 606”). The core principle of the new standard is for companies to recognize revenue to depict the transfer of goods and services to patients in amounts that reflect the consideration to which the company expects to be entitled in exchange for those goods and services. In addition, the new standard requires expanded disclosures. The Company has adopted the standard effective January 1, 2018 using the modified retrospective method for all contracts. The reported results for 2018 reflect the application of ASC 606 guidance while the reported results for 2017 were prepared under the guidance of ASC 605, Revenue Recognition (ASC 605). The amount of revenue recognized in 2018 reflects the consideration to which the Company expects to be entitled to receive in exchange for Optune. In preparation for adoption of the standard, the Company has implemented internal controls and key system functionality to enable the preparation of financial information, including the assessment of the impact of the standard. The Company uses the portfolio approach to apply the standard to portfolios of contracts with similar characteristics. Adoption of the standard resulted in an increase to trade receivables of $2,807, deferred revenues of $645 and a cumulative impact to the Company's accumulated deficit as of January 1, 2018 of $2,162. Optune is comprised of two main components: (1) an electric field generator and (2) transducer arrays and related accessories. We retain title to the electric field generator, and the patient is provided replacement transducer arrays and technical support for the device during the term of treatment. The electric field generator and transducer arrays are always supplied and function together and are not sold on a standalone basis. To recognize revenue under ASC 606, the Company applies the following five steps: 1. Identify the contract with a patient. A contract with a patient exists when (i) the Company enters into an enforceable contract with a patient that defines each party’s rights regarding delivery of and payment for Optune, (ii) the contract has commercial substance and (iii) the Company determines that collection of substantially all consideration for Optune is probable based on the payer’s intent and ability to pay the promised consideration. The evidence of a contract generally consists of a prescription, a patient service agreement and the verification of the assigned payer for the contract and intention to collect. 2. Identify the performance obligations in the contract. Optune contracts include the lease of the device, the supply obligation of disposable transducer arrays and technical support for the term of treatment. To the extent a contract includes multiple promised products and/or services, the Company must apply judgment to determine whether those products and/or services are capable of being distinct in the context of the contract. If these criteria are not met the promised products and/or services are accounted for as a combined performance obligation. In the Company’s case, Optune’s device, support, and disposables are provided as one inseparable package of monthly treatment for a single monthly fee. 3. Determine the transaction price. The transaction price is determined based on the consideration to which the Company will be entitled in exchange for providing Optune to the patient. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. The Company has agreements with many payers that define explicit discounts off the gross transaction price. In addition to the explicit discounts negotiated with each payer, the Company expects to receive, in aggregate for a given portfolio, less than the gross revenue net of explicit discounts. ASC 606 requires that the Company recognize this variable consideration as an implicit discount in the billing period. The implicit discount includes both an estimate of claims that will pay at an amount less than billed and an estimate of claims that will not pay within a given time horizon. The implicit discount adjustments to the transaction price are due to concessions, not collectability concerns driven by payer credit risk. 4. Allocate the transaction price to performance obligations in the contract. If a contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. As discussed above, there is one performance obligation under the Company’s contracts and, therefore, the monthly transaction price determined for the performance obligation will be recognized over time ratably over the monthly term of the treatment. 5. Recognize revenue when or as the Company satisfies a performance obligation. The Company satisfies performance obligations over time as discussed above. Revenue is recognized at the time the related performance obligation is satisfied by transferring a promised service to a patient. The patient consumes the benefits of Optune treatment on a daily basis over the monthly term. As this criterion is met, the revenues will be recognized over the monthly term. In accordance with ASC 606, the impact of our adoption of ASC 606 on our condensed consolidated statements of income for the six and three months ended June 30, 2018 were a decrease in net revenues of $5,531 and $1,993, respectively, an increase in net loss of $5,371 and $2,035, respectively, and a decrease in our basic and diluted net loss per ordinary share of $0.06 and $0.02, respectively. The impact of our adoption of Topic 606 on our balance sheet as of June 30, 2018 was a decrease in trade receivables of $2,760, an increase to other payables and accrued expenses (deferred revenues net of tax provision) of $521 and an accumulated deficit as of June 30, 2018 of $3,209. In August 2016, FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments. ASU 2016-15 eliminates the diversity in practice related to the classification of certain cash receipts and payments for debt prepayment or extinguishment costs, the maturing of a zero coupon bond, the settlement of contingent liabilities arising from a business combination, proceeds from insurance settlements, distributions from certain equity method investees and beneficial interests obtained in a financial asset securitization. ASU 2016-15 designates the appropriate cash flow classification, including requirements to allocate certain components of these cash receipts and payments among operating, investing and financing activities. The retrospective transition method, requiring adjustment to all comparative periods presented, is required unless it is impracticable for some of the amendments, in which case those amendments would be prospectively as of the earliest date practicable. The Company adopted the standard effective as of January 1, 2018, and the adoption of this standard did not have an impact on the Company's consolidated financial statements. In November 2016, FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. This standard requires the presentation of the statement of cash flows to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. The standard is effective for fiscal years and the interim periods within those fiscal years beginning after December 15, 2017. The Company adopted the standard retrospectively to all periods presented effective as of January 1, 2018. Recent Accounting Pronouncements. In February 2016, FASB issued ASU 2016-02-Leases (ASC 842), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than twelve months regardless of their classification. Leases with a term of twelve months or less will be accounted for similar to existing guidance for operating leases. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases and operating leases. ASC 842 supersedes the previous leases standard, ASC 840. The standard is effective on January 1, 2019, with early adoption permitted. The Company currently anticipates adopting the new standard effective January 1, 2019 and is evaluating the impact of the adoption of this standard on its consolidated financial statements. In June 2016, FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 amends the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology, which will result in the more timely recognition of losses. ASU 2016-13 also applies to employee benefit plan accounting, with an effective date of the first quarter of fiscal 2020. The amendments in this update are effective for fiscal years beginning after December 31, 2019, including interim periods within those fiscal years. The Company is currently assessing the impact of the adoption of this standard on its consolidated financial statements, footnote disclosures and employee benefit plans’ accounting. In June 2018, FASB issued ASU 2018-07 to expand the scope of ASC Topic 718, Compensation - Stock Compensation, to include share-based payment transactions for acquiring goods and services from nonemployees. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The Company is evaluating the effects of this standard on its consolidated financial statements.

Short-Term Investments	6 Months Ended
Short-Term Investments	Jun. 30, 2018
Debt Securities Current [Abstract]
Short-Term Investments	NOTE 2: SHORT-TERM INVESTMENTS The Company invests in marketable U.S. Treasury Bills (“T-bills”) that are classified as held-to-maturity securities. The amortized cost and recorded basis of the T-bills are presented as short-term investments in the amount of $104,499 and $104,719 as of June 30, 2018 and December 31, 2017, respectively, and their estimated fair value as of June 30, 2018 and December 31, 2017 was $104,512 and $104,655, respectively.

Inventories

6 Months Ended

Jun. 30, 2018

Inventory Disclosure [Abstract]

Inventories

NOTE 3: INVENTORIES

Inventories are stated at the lower of cost or market. The weighted average methodology is applied to determine cost. As of June 30, 2018 and December 31, 2017, the Company’s inventories were composed of:

	June 30,		December 31,
	2018		2017
	Unaudited		Audited
Raw materials	$	2,519	$	4,276
Work in progress		5,267		8,435
Finished products		12,120		9,314
Total	$	19,906	$	22,025

Commitments and Contingent Liabilities	6 Months Ended
Commitments and Contingent Liabilities	Jun. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	NOTE 4: COMMITMENTS AND CONTINGENT LIABILITIES The facilities of the Company are leased under various operating lease agreements for periods ending no later than 2024. The Company also leases motor vehicles under various operating leases, which expire on various dates, the latest of which is in 2021. As of June 30, 2018 and December 31, 2017, the Company pledged bank deposits of $1,145 and $1,038, respectively, to cover bank guarantees in respect of its leases of operating facilities and obtained bank guarantees for the fulfillment of the Company’s lease and other contractual commitments of $1,305 and $1,202, respectively. In the first quarter of 2018, the Company made a milestone payment of $5.5 million (the “Milestone Payment”) to the Technion Research and Development Foundation (“Technion”) pursuant to the settlement agreement dated February 10, 2015 (the “Settlement Agreement”). Pursuant to the Settlement Agreement, and in exchange for a release of potential disputes regarding intellectual property developed by our founder and previously assigned to us, the Company was obligated to pay the Milestone Payment to Technion in the quarter following the quarter in which the Company achieved $250.0 million of cumulative net sales (as defined in the Settlement Agreement) (the “Net Sales Milestone”). The Company achieved the Net Sales Milestone in the fourth quarter of 2017.

Long Term Loan	6 Months Ended
Long Term Loan	Jun. 30, 2018
Debt Disclosure [Abstract]
Long Term Loan	NOTE 5: LONG TERM LOAN On February 7, 2018, the Company and certain of its subsidiaries entered into a Loan and Security Agreement (“2018 Loan Agreement”) with BioPharma Credit PLC pursuant to which such lender made a term loan to the Company in the principal amount of $150 million (the “2018 Credit Facility”). The term loan, which was drawn in full upon execution of the 2018 Loan Agreement, bears interest at 9.0% per annum, payable quarterly in arrears. The Company used a portion of the proceeds of the 2018 Credit Facility to repay in full the Company’s obligations under its existing term loan credit facility and will use the remaining proceeds to fund general corporate purposes. The 2018 Credit Facility will mature on February 7, 2023, at which time any unpaid principal and accrued unpaid interest in respect of the term loan will be due and payable. The Company may prepay the term loan, in full, at any time. The Company must prepay the term loan (i) in full or in part upon the entry into certain licensing arrangements and (ii) in full in the event of a change of control. In each case, any prepayment (whether permitted or mandatory) is subject to a prepayment premium and/or make-whole payment. The pre-payment fee if the Company prepays outstanding loan amounts prior to February 7, 2021 is 2.0% and is 1.0% if made after the February 7, 2021 but prior to February 7, 2022. All obligations under the 2018 Credit Facility are guaranteed by the Company’s current and future direct and indirect subsidiaries. In addition, the obligations under the 2018 Credit Facility are secured by a first-priority security interest in substantially all of the property and assets of, as well as the equity interests owned by, the Company and certain of the other guarantors. The 2018 Credit Facility contains other customary covenants. Total net issuance costs of the 2018 Credit Facility, which were $805 as of June 30, 2018, are presented net of the 2018 Credit Facility proceeds and are amortized to interest expense over the five year term of the loan using the effective interest method. On February 7, 2018, the Company’s 2015 term loan credit facility was terminated upon the Company’s repayment in full of the term loan issued thereunder. The un-amortized discount in the amount of $1,160 and issuance costs in the amount of $1,399 were fully amortized and included in the Company’s first quarter finance expenses.

Share Capital	6 Months Ended
Share Capital	Jun. 30, 2018
Share Based Compensation Allocation And Classification In Financial Statements [Abstract]
Share Capital	NOTE 6: SHARE CAPITAL For the six months ended June 30, 2018, warrants to purchase 201,692 ordinary shares with an exercise price of $3.59 per share were cashlessly exercised, resulting in the issuance of 167,212 ordinary shares. Also, warrants to purchase 1,549 ordinary shares with an exercise price of $3.59 per share were exercised for cash. For the six months ended June 30, 2018, options to purchase 2,253,654 ordinary shares were exercised, resulting in the issuance of 2,251,676 ordinary shares.

Equity Incentive Plans

6 Months Ended

Jun. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Equity Incentive Plans

NOTE 7: EQUITY INCENTIVE PLANS

In September 2015, the Company adopted the 2015 Omnibus Incentive Plan (the “2015 Plan”). Under the 2015 Plan, the Company can issue various types of equity compensation awards such as share options, restricted shares, performance shares, restricted stock units (“RSUs”), performance units, long-term cash awards and other share-based awards.

Options granted under the 2015 Plan generally have a four-year vesting period and expire ten years after the date of grant. Options granted under the 2015 Plan that are cancelled or forfeited before expiration become available for future grants. RSUs granted under the 2015 Plan vest in equal installments over a three-year period. As of June 30, 2018, 10,416,052 ordinary shares were available for grant under the 2015 Plan.

A summary of the status of the Company’s option plans as of June 30, 2018 and changes during the period then ended is presented below:

	Six months ended June 30, 2018
	Unaudited
	Number of options			Weighted average exercise price
Outstanding at beginning of year		14,806,027		$	10.64
Granted		2,199,389			22.31
Exercised		(2,253,654	)		6.54
Forfeited and cancelled		(127,262	)		14.59
Outstanding as of June 30, 2018		14,624,500		$	12.99

Exercisable options		5,955,869		$	10.20

A summary of the status of the Company’s RSUs as of June 30, 2018 and changes during the period then ended is presented below:

	Six months ended June 30, 2018
	Unaudited
	Number of RSUs			Weighted average grant date fair value price
Unvested at beginning of year		1,651,219		$	9.66
Granted		482,232			22.20
Vested		(550,418	)		9.66
Forfeited and cancelled		(10,760	)		12.13
Unvested as of June 30, 2018		1,572,273		$	13.49

In September 2015, the Company adopted an employee share purchase plan (“ESPP”) to encourage and enable eligible employees to acquire ownership of the Company’s ordinary shares purchased through accumulated payroll deductions on an after-tax basis. In the United States, the ESPP is intended to be an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code and the provisions of the ESPP will be construed in a manner consistent with the requirements of such section. The Company began its offerings under the ESPP on August 1, 2016. As of June 30, 2018, 2,223,319 ordinary shares were available to be purchased by eligible employees under the ESPP and 314,207 shares had been issued under the ESPP.

The fair value of share-based awards was estimated using the Black-Scholes model for all equity grants. For market condition awards, the Company also applied the Monte-Carlo simulation model, with the following underlying assumptions:

	Six months ended June 30,		Year ended December 31,
	2018	2017	2017
	Unaudited		Audited
Stock Option Plans
Expected term (years)	5.50-6.25	5.50-6.25	5.50-6.25
Expected volatility	52%-55%	57%-59%	57%-59%
Risk-free interest rate	2.70%-2.89%	1.99%-2.23%	1.97%-2.23%
Dividend yield	0.00%	0.00%	0.00%
ESPP
Expected term (years)	0.50	0.50	0.50
Expected volatility	53%	82%	76%-82%
Risk-free interest rate	1.61%	0.62%	0.62%-1.13%
Dividend yield	0.00%	0.00%	0.00%

The total non-cash share-based compensation expense related to all of the Company’s equity-based awards recognized for the three and six months ended June 30, 2018 and 2017 and the year ended December 31, 2017 was:

	Three months ended June 30,				Six months ended June 30,				Year ended December 31,
	2018		2017		2018		2017		2017
	Unaudited				Unaudited				Audited
Cost of revenues	$	263	$	131	$	428	$	274	$	467
Research, development and clinical trials		1,286		811		2,192		1,673		3,587
Sales and marketing		1,893		1,735		3,329		2,390		3,784
General and administrative		6,764		4,893		12,777		7,794		19,278
Total share-based compensation expense	$	10,206	$	7,570	$	18,726	$	12,131	$	27,116

Supplemental Information

6 Months Ended

Jun. 30, 2018

Geographic Areas Long Lived Assets [Abstract]

Supplemental Information

NOTE 8: SUPPLEMENTAL INFORMATION

The Company operates in a single reportable segment.

The following table presents long-lived assets by location:

	June 30,		December 31,
	2018		2017
	Unaudited		Audited
United States	$	9,731	$	10,372
Switzerland		4,211		5,114
Israel		2,238		2,081
Others		819		500
Total	$	16,999	$	18,067

The Company’s revenues by geographic region, based on the customer’s location, are summarized as follows:

	Three months ended June 30,				Six months ended June 30,				Year ended December 31,
	2018		2017		2018		2017		2017
	Unaudited				Unaudited				Audited
United States	$	41,935	$	31,367	$	79,738	$	60,526	$	134,688
EMEA (*)		18,522		6,891		32,396		12,559		42,035
Japan		1,057		118		1,505		171		303
Total	$	61,514	$	38,376	$	113,639	$	73,256	$	177,026

(*) including Germany	$	17,651	$	6,817	$	31,009	$	12,216	$	40,215

Organization and Basis of Presentation (Policies)	6 Months Ended
Organization and Basis of Presentation (Policies)	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements. In May 2014, FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09), an updated standard on revenue recognition and issued subsequent amendments to the initial guidance in March 2016, April 2016, May 2016 and December 2016 within ASU 2016-08, 2016-10, 2016-12 and 2016-20, respectively (collectively, “ASC 606”). The core principle of the new standard is for companies to recognize revenue to depict the transfer of goods and services to patients in amounts that reflect the consideration to which the company expects to be entitled in exchange for those goods and services. In addition, the new standard requires expanded disclosures. The Company has adopted the standard effective January 1, 2018 using the modified retrospective method for all contracts. The reported results for 2018 reflect the application of ASC 606 guidance while the reported results for 2017 were prepared under the guidance of ASC 605, Revenue Recognition (ASC 605). The amount of revenue recognized in 2018 reflects the consideration to which the Company expects to be entitled to receive in exchange for Optune. In preparation for adoption of the standard, the Company has implemented internal controls and key system functionality to enable the preparation of financial information, including the assessment of the impact of the standard. The Company uses the portfolio approach to apply the standard to portfolios of contracts with similar characteristics. Adoption of the standard resulted in an increase to trade receivables of $2,807, deferred revenues of $645 and a cumulative impact to the Company's accumulated deficit as of January 1, 2018 of $2,162. Optune is comprised of two main components: (1) an electric field generator and (2) transducer arrays and related accessories. We retain title to the electric field generator, and the patient is provided replacement transducer arrays and technical support for the device during the term of treatment. The electric field generator and transducer arrays are always supplied and function together and are not sold on a standalone basis. To recognize revenue under ASC 606, the Company applies the following five steps: 1. Identify the contract with a patient. A contract with a patient exists when (i) the Company enters into an enforceable contract with a patient that defines each party’s rights regarding delivery of and payment for Optune, (ii) the contract has commercial substance and (iii) the Company determines that collection of substantially all consideration for Optune is probable based on the payer’s intent and ability to pay the promised consideration. The evidence of a contract generally consists of a prescription, a patient service agreement and the verification of the assigned payer for the contract and intention to collect. 2. Identify the performance obligations in the contract. Optune contracts include the lease of the device, the supply obligation of disposable transducer arrays and technical support for the term of treatment. To the extent a contract includes multiple promised products and/or services, the Company must apply judgment to determine whether those products and/or services are capable of being distinct in the context of the contract. If these criteria are not met the promised products and/or services are accounted for as a combined performance obligation. In the Company’s case, Optune’s device, support, and disposables are provided as one inseparable package of monthly treatment for a single monthly fee. 3. Determine the transaction price. The transaction price is determined based on the consideration to which the Company will be entitled in exchange for providing Optune to the patient. To the extent the transaction price includes variable consideration, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in the Company’s judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. The Company has agreements with many payers that define explicit discounts off the gross transaction price. In addition to the explicit discounts negotiated with each payer, the Company expects to receive, in aggregate for a given portfolio, less than the gross revenue net of explicit discounts. ASC 606 requires that the Company recognize this variable consideration as an implicit discount in the billing period. The implicit discount includes both an estimate of claims that will pay at an amount less than billed and an estimate of claims that will not pay within a given time horizon. The implicit discount adjustments to the transaction price are due to concessions, not collectability concerns driven by payer credit risk. 4. Allocate the transaction price to performance obligations in the contract. If a contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. As discussed above, there is one performance obligation under the Company’s contracts and, therefore, the monthly transaction price determined for the performance obligation will be recognized over time ratably over the monthly term of the treatment. 5. Recognize revenue when or as the Company satisfies a performance obligation. The Company satisfies performance obligations over time as discussed above. Revenue is recognized at the time the related performance obligation is satisfied by transferring a promised service to a patient. The patient consumes the benefits of Optune treatment on a daily basis over the monthly term. As this criterion is met, the revenues will be recognized over the monthly term. In accordance with ASC 606, the impact of our adoption of ASC 606 on our condensed consolidated statements of income for the six and three months ended June 30, 2018 were a decrease in net revenues of $5,531 and $1,993, respectively, an increase in net loss of $5,371 and $2,035, respectively, and a decrease in our basic and diluted net loss per ordinary share of $0.06 and $0.02, respectively. The impact of our adoption of Topic 606 on our balance sheet as of June 30, 2018 was a decrease in trade receivables of $2,760, an increase to other payables and accrued expenses (deferred revenues net of tax provision) of $521 and an accumulated deficit as of June 30, 2018 of $3,209. In August 2016, FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments. ASU 2016-15 eliminates the diversity in practice related to the classification of certain cash receipts and payments for debt prepayment or extinguishment costs, the maturing of a zero coupon bond, the settlement of contingent liabilities arising from a business combination, proceeds from insurance settlements, distributions from certain equity method investees and beneficial interests obtained in a financial asset securitization. ASU 2016-15 designates the appropriate cash flow classification, including requirements to allocate certain components of these cash receipts and payments among operating, investing and financing activities. The retrospective transition method, requiring adjustment to all comparative periods presented, is required unless it is impracticable for some of the amendments, in which case those amendments would be prospectively as of the earliest date practicable. The Company adopted the standard effective as of January 1, 2018, and the adoption of this standard did not have an impact on the Company's consolidated financial statements. In November 2016, FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. This standard requires the presentation of the statement of cash flows to show the changes in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. The standard is effective for fiscal years and the interim periods within those fiscal years beginning after December 15, 2017. The Company adopted the standard retrospectively to all periods presented effective as of January 1, 2018. Recent Accounting Pronouncements. In February 2016, FASB issued ASU 2016-02-Leases (ASC 842), which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both parties to a contract (i.e. lessees and lessors). The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight line basis over the term of the lease, respectively. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than twelve months regardless of their classification. Leases with a term of twelve months or less will be accounted for similar to existing guidance for operating leases. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases and operating leases. ASC 842 supersedes the previous leases standard, ASC 840. The standard is effective on January 1, 2019, with early adoption permitted. The Company currently anticipates adopting the new standard effective January 1, 2019 and is evaluating the impact of the adoption of this standard on its consolidated financial statements. In June 2016, FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 amends the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology, which will result in the more timely recognition of losses. ASU 2016-13 also applies to employee benefit plan accounting, with an effective date of the first quarter of fiscal 2020. The amendments in this update are effective for fiscal years beginning after December 31, 2019, including interim periods within those fiscal years. The Company is currently assessing the impact of the adoption of this standard on its consolidated financial statements, footnote disclosures and employee benefit plans’ accounting. In June 2018, FASB issued ASU 2018-07 to expand the scope of ASC Topic 718, Compensation - Stock Compensation, to include share-based payment transactions for acquiring goods and services from nonemployees. The pronouncement is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. The Company is evaluating the effects of this standard on its consolidated financial statements.

Inventories (Tables)

6 Months Ended

Jun. 30, 2018

Inventory Disclosure [Abstract]

Schedule of Inventories

Inventories are stated at the lower of cost or market. The weighted average methodology is applied to determine cost. As of June 30, 2018 and December 31, 2017, the Company’s inventories were composed of:

	June 30,		December 31,
	2018		2017
	Unaudited		Audited
Raw materials	$	2,519	$	4,276
Work in progress		5,267		8,435
Finished products		12,120		9,314
Total	$	19,906	$	22,025

Equity Incentive Plans (Tables)

6 Months Ended

Jun. 30, 2018

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Stock Option Plans

A summary of the status of the Company’s option plans as of June 30, 2018 and changes during the period then ended is presented below:

	Six months ended June 30, 2018
	Unaudited
	Number of options			Weighted average exercise price
Outstanding at beginning of year		14,806,027		$	10.64
Granted		2,199,389			22.31
Exercised		(2,253,654	)		6.54
Forfeited and cancelled		(127,262	)		14.59
Outstanding as of June 30, 2018		14,624,500		$	12.99

Exercisable options		5,955,869		$	10.20

Schedule of RSU's

A summary of the status of the Company’s RSUs as of June 30, 2018 and changes during the period then ended is presented below:

	Six months ended June 30, 2018
	Unaudited
	Number of RSUs			Weighted average grant date fair value price
Unvested at beginning of year		1,651,219		$	9.66
Granted		482,232			22.20
Vested		(550,418	)		9.66
Forfeited and cancelled		(10,760	)		12.13
Unvested as of June 30, 2018		1,572,273		$	13.49

Schedule of Fair Value Assumptions Used for All Equity Based Awards Estimated Using Black-Scholes Option Pricing Model

The fair value of share-based awards was estimated using the Black-Scholes model for all equity grants. For market condition awards, the Company also applied the Monte-Carlo simulation model, with the following underlying assumptions:

	Six months ended June 30,		Year ended December 31,
	2018	2017	2017
	Unaudited		Audited
Stock Option Plans
Expected term (years)	5.50-6.25	5.50-6.25	5.50-6.25
Expected volatility	52%-55%	57%-59%	57%-59%
Risk-free interest rate	2.70%-2.89%	1.99%-2.23%	1.97%-2.23%
Dividend yield	0.00%	0.00%	0.00%
ESPP
Expected term (years)	0.50	0.50	0.50
Expected volatility	53%	82%	76%-82%
Risk-free interest rate	1.61%	0.62%	0.62%-1.13%
Dividend yield	0.00%	0.00%	0.00%

Schedule of Non-cash Share-based Compensation Expense Related to Company's Equity-Based Awards

The total non-cash share-based compensation expense related to all of the Company’s equity-based awards recognized for the three and six months ended June 30, 2018 and 2017 and the year ended December 31, 2017 was:

	Three months ended June 30,				Six months ended June 30,				Year ended December 31,
	2018		2017		2018		2017		2017
	Unaudited				Unaudited				Audited
Cost of revenues	$	263	$	131	$	428	$	274	$	467
Research, development and clinical trials		1,286		811		2,192		1,673		3,587
Sales and marketing		1,893		1,735		3,329		2,390		3,784
General and administrative		6,764		4,893		12,777		7,794		19,278
Total share-based compensation expense	$	10,206	$	7,570	$	18,726	$	12,131	$	27,116

Supplemental Information (Tables)

6 Months Ended

Jun. 30, 2018

Geographic Areas Long Lived Assets [Abstract]

Schedule of Long-Lived Assets by Location

The following table presents long-lived assets by location:

	June 30,		December 31,
	2018		2017
	Unaudited		Audited
United States	$	9,731	$	10,372
Switzerland		4,211		5,114
Israel		2,238		2,081
Others		819		500
Total	$	16,999	$	18,067

Schedule of Revenues by Geographic Region

The Company’s revenues by geographic region, based on the customer’s location, are summarized as follows:

	Three months ended June 30,				Six months ended June 30,				Year ended December 31,
	2018		2017		2018		2017		2017
	Unaudited				Unaudited				Audited
United States	$	41,935	$	31,367	$	79,738	$	60,526	$	134,688
EMEA (*)		18,522		6,891		32,396		12,559		42,035
Japan		1,057		118		1,505		171		303
Total	$	61,514	$	38,376	$	113,639	$	73,256	$	177,026

(*) including Germany	$	17,651	$	6,817	$	31,009	$	12,216	$	40,215

Organization and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Organization and Basis of Presentation [Line Items]
Increase (decrease) in trade receivables	$ 3,599	$ 2,064	$ 5,271	$ 7,550	$ 23,228
Decrease in net revenue	61,514	38,376	113,639	73,256	177,026
Net loss	$ (15,510)	$ (21,174)	$ (36,234)	$ (39,219)	$ (61,662)
Decrease in basic and diluted net loss per ordinary share	$ (0.17)	$ (0.24)	$ (0.40)	$ (0.45)	$ (0.70)
Increase in other payables and accrued expenses	$ (528)	$ 4,888	$ (8,828)	$ 3,478	$ 14,460
Accounting Standards Update 2014-09 [Member]
Organization and Basis of Presentation [Line Items]
Increase (decrease) in trade receivables			(2,760)		2,807
Increase in deferred revenue					645
Cumulative deficit effect adjustment resulting from ASU 2014-09 adoption	(3,209)		(3,209)		$ (2,162)
Net loss	$ (2,035)		$ (5,371)
Decrease in basic and diluted net loss per ordinary share	$ (0.02)		$ (0.06)
Increase in other payables and accrued expenses			$ 521
Accounting Standards Update 2014-09 [Member] \| Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Organization and Basis of Presentation [Line Items]
Decrease in net revenue	$ (1,993)		$ (5,531)
Accounting Standards Update 2014-09 [Member] \| First Generation Optune System Field Equipment [Member]
Organization and Basis of Presentation [Line Items]
Identify the contract with patient			Identify the contract with a patient. A contract with a patient exists when (i) the Company enters into an enforceable contract with a patient that defines each party’s rights regarding delivery of and payment for Optune, (ii) the contract has commercial substance and (iii) the Company determines that collection of substantially all consideration for Optune is probable based on the payer’s intent and ability to pay the promised consideration. The evidence of a contract generally consists of a prescription, a patient service agreement and the verification of the assigned payer for the contract and intention to collect.
Identify the performance obligations in the contract, description			Optune contracts include the lease of the device, the supply obligation of disposable transducer arrays and technical support for the term of treatment. To the extent a contract includes multiple promised products and/or services, the Company must apply judgment to determine whether those products and/or services are capable of being distinct in the context of the contract. If these criteria are not met the promised products and/or services are accounted for as a combined performance obligation. In the Company’s case, Optune’s device, support, and disposables are provided as one inseparable package of monthly treatment for a single monthly fee
Determine the transaction price, description			The transaction price is determined based on the consideration to which the Company will be entitled in exchange for providing Optune to the patient.
Allocate the transaction price to performance obligations in the contract, description			If a contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. As discussed above, there is one performance obligation under the Company’s contracts and, therefore, the monthly transaction price determined for the performance obligation will be recognized over time ratably over the monthly term of the treatment.
Recognize revenue when or as the company satisfies a performance obligation, description			The Company satisfies performance obligations over time as discussed above. Revenue is recognized at the time the related performance obligation is satisfied by transferring a promised service to a patient. The patient consumes the benefits of Optune treatment on a daily basis over the monthly term. As this criterion is met, the revenues will be recognized over the monthly term.

Short-Term Investments - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Short-term investments	$ 104,499	$ 104,719
Estimated fair value of short-term investments	$ 104,512	$ 104,655

Inventories - Schedule of Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 2,519	$ 4,276
Work in progress	5,267	8,435
Finished products	12,120	9,314
Total	$ 19,906	$ 22,025

Commitments and Contingent Liabilities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Operating lease expiration description		The facilities of the Company are leased under various operating lease agreements for periods ending no later than 2024.
Pledged bank deposits		$ 1,145	$ 1,038
Operating lease and other contractual commitments		1,305	$ 1,202
Settlement agreement date	February 10, 2015
Settlement Agreement
Loss Contingencies [Line Items]
Settlement expense	$ 5,500
Net sales milestone		$ 250,000
Motor Vehicles
Loss Contingencies [Line Items]
Operating lease expiration description		The Company also leases motor vehicles under various operating leases, which expire on various dates, the latest of which is in 2021.
Maximum
Loss Contingencies [Line Items]
Operating lease agreements, expiration year		2024
Maximum \| Motor Vehicles
Loss Contingencies [Line Items]
Operating lease agreements, expiration year		2021

Long Term Loan - Additional Information (Details) - USD ($) $ in Thousands		6 Months Ended
	Feb. 07, 2018	Jun. 30, 2018
2018 Credit Facility
Line Of Credit Facility [Line Items]
Term loan, principal amount	$ 150,000
Interest on term loan credit facility	9.00%
Interest, frequency of payment	quarterly
Term loan credit facility, expiation date	Feb. 07, 2023
Debt issuance costs, net		$ 805
Term loan credit facility, maturity term		5 years
2018 Credit Facility \| Prior to February 7, 2021
Line Of Credit Facility [Line Items]
Pre-payment fee, percentage	2.00%
2018 Credit Facility \| February 7, 2021 to February 7, 2022
Line Of Credit Facility [Line Items]
Pre-payment fee, percentage	1.00%
Term Loan
Line Of Credit Facility [Line Items]
Debt issuance costs, net	$ 1,399
Debt instrument, un-amortized discount	$ 1,160

Share Capital - Additional Information (Details)	6 Months Ended
Share Capital - Additional Information (Details)	Jun. 30, 2018 $ / shares shares
Share Capital [Line Items]
The Number of ordinary shares that originally could be purchased by exercise of warrants	201,692
Warrants exercise price \| $ / shares	$ 3.59
Options exercised	2,253,654
Ordinary shares issued upon option exercise	2,251,676
Warrant
Share Capital [Line Items]
The Number of ordinary shares that originally could be purchased by exercise of warrants in cash	1,549
Warrant \| Warrants Not Settleable in Cash
Share Capital [Line Items]
Number of shares issued upon the exercise of warrants	167,212

Equity Incentive Plans - Additional Information (Details)	6 Months Ended
	Jun. 30, 2018 shares
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Ordinary shares available for grants	2,223,319
Shares issued under plan	314,207
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Ordinary shares available for grants	10,416,052
2015 Plan \| Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards granted, vesting period	4 years
Stock awards granted, expiration period	10 years
2015 Plan \| RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock awards granted, vesting period	3 years

Equity Incentive Plans - Schedule of Stock Option Plan (Details)	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Number of options
Number of options, Outstanding at beginning of year \| shares	14,806,027
Number of options, Granted \| shares	2,199,389
Number of options, Exercised \| shares	(2,253,654)
Number of options, Forfeited and cancelled \| shares	(127,262)
Number of options, Outstanding at ending of year \| shares	14,624,500
Number of options, Exercisable options \| shares	5,955,869
Weighted average exercise price
Weighted average exercise price, Outstanding at beginning of year \| $ / shares	$ 10.64
Weighted average exercise price, Granted \| $ / shares	22.31
Weighted average exercise price, Exercised \| $ / shares	6.54
Weighted average exercise price, Forfeited and cancelled \| $ / shares	14.59
Weighted average exercise price, Outstanding at end of year \| $ / shares	12.99
Weighted average exercise price, Exercisable options \| $ / shares	$ 10.20

Equity Incentive Plans - Schedule of RSU's (Details) - RSUs	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Number of RSUs
Number of RSUs, unvested at beginning of year \| shares	1,651,219
Number of RSUs, granted \| shares	482,232
Number of RSUs, vested \| shares	(550,418)
Number of RSUs, forfeited and cancelled \| shares	(10,760)
Number of RSUs, unvested at ending of year \| shares	1,572,273
Weighted average grant date fair value price
Weighted average grant date date fair value price, unvested at beginning of year \| $ / shares	$ 9.66
Weighted average grant date date fair value price, granted \| $ / shares	22.20
Weighted average grant date date fair value price, vested \| $ / shares	9.66
Weighted average grant date date fair value price, forfeited and cancelled \| $ / shares	12.13
Weighted average grant date date fair value price, unvested at ending of year \| $ / shares	$ 13.49

Equity Incentive Plans - Schedule of Fair Value Assumptions Used for All Equity Based Awards Estimated Using Black-Scholes Option Pricing Model (Details)	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Stock Option Plans
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum	52.00%	57.00%	57.00%
Expected volatility, maximum	55.00%	59.00%	59.00%
Risk-free interest rate, minimum	2.70%	1.99%	1.97%
Risk-free interest rate, maximum	2.89%	2.23%	2.23%
Dividend yield	0.00%	0.00%	0.00%
Stock Option Plans \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 6 months	5 years 6 months	5 years 6 months
Stock Option Plans \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 years 3 months	6 years 3 months	6 years 3 months
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	6 months	6 months	6 months
Expected volatility	53.00%	82.00%
Expected volatility, minimum			76.00%
Expected volatility, maximum			82.00%
Risk-free interest rate	1.61%	0.62%
Risk-free interest rate, minimum			0.62%
Risk-free interest rate, maximum			1.13%
Dividend yield	0.00%	0.00%	0.00%

Equity Incentive Plans - Schedule of Non-cash Share-Based Compensation Expenses Related to Company's Equity-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 10,206	$ 7,570	$ 18,726	$ 12,131	$ 27,116
Cost of Revenues
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	263	131	428	274	467
Research, Development and Clinical Trials
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	1,286	811	2,192	1,673	3,587
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	1,893	1,735	3,329	2,390	3,784
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 6,764	$ 4,893	$ 12,777	$ 7,794	$ 19,278

Supplemental Information - Schedule of Long-Lived Assets by Location (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	$ 16,999	$ 18,067
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	9,731	10,372
Switzerland
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	4,211	5,114
Israel
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	2,238	2,081
Others
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	$ 819	$ 500

Supplemental Information - Schedule of Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 61,514	$ 38,376	$ 113,639	$ 73,256	$ 177,026
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	41,935	31,367	79,738	60,526	134,688
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	18,522	6,891	32,396	12,559	42,035
Japan
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 1,057	$ 118	$ 1,505	$ 171	$ 303

Supplemental Information - Schedule of Revenues by Geographic Region (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 61,514	$ 38,376	$ 113,639	$ 73,256	$ 177,026
Germany
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenues	$ 17,651	$ 6,817	$ 31,009	$ 12,216	$ 40,215