Criteo (CRTO) 10-K 1 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Jan. 31, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Criteo S.A.
Entity Central Index Key	1,576,427
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Entity Common Stock, Shares Outstanding (in shares)		63,990,003
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 2.7

Consolidated Statements of Fina

Consolidated Statements of Financial Position - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 270,317	$ 353,537
Trade receivables, net of allowances	397,244	261,581
Income taxes	2,741	2,714
Other taxes	52,942	29,552
Other current assets	19,340	16,030
Total current assets	742,584	663,414
Property, plant and equipment, net	108,581	82,482
Intangible assets, net	102,944	16,470
Goodwill	209,418	41,973
Non-current financial assets	17,029	17,184
Deferred tax assets	30,630	20,196
Total non current assets	468,602	178,305
Total assets	1,211,186	841,719
Current liabilities:
Trade payables	365,788	246,382
Contingencies	654	668
Income taxes	14,454	15,365
Financial liabilities - current portion	7,969	7,156
Other taxes	44,831	30,463
Employee-related payables	55,874	42,275
Other current liabilities	30,221	15,531
Total current liabilities	519,791	357,840
Deferred tax liabilities	686	139
Retirement benefit obligation	3,221	1,445
Financial liabilities - non current portion	77,611	3,272
Total non-current liabilities	81,518	4,856
Total liabilities	601,309	362,696
Commitments and contingencies
Shareholders' equity:
Common shares, €0.025 per value, 62,470,881 and 63,978,204 shares authorized, issued and outstanding at December 31, 2015 and 2016, respectively.	2,093	2,052
Additional paid-in capital	488,277	425,220
Accumulated other comprehensive income (loss)	(88,593)	(69,023)
Retained earnings	198,355	116,076
Equity - attributable to shareholders of Criteo S.A.	600,132	474,325
Non-controlling interests	9,745	4,698
Total equity	609,877	479,023
Total equity and liabilities	$ 1,211,186	$ 841,719

Consolidated Statements of Fin3

Consolidated Statements of Financial Position (Parenthetical) - € / shares	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common shares, par value (in Euro per share)	€ 0.025	€ 0.025
Common shares authorized (in shares)	63,978,204	62,470,881
Common shares issued (in shares)	63,978,204	62,470,881
Common shares outstanding (in shares)	63,978,204	62,470,881

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue	$ 1,799,146	$ 1,323,169	$ 988,249
Cost of revenue
Traffic acquisition costs	(1,068,911)	(789,152)	(585,492)
Other cost of revenue	(85,260)	(62,201)	(47,948)
Gross profit	644,975	471,816	354,809
Operating expenses:
Research and development expenses	(123,649)	(86,807)	(60,075)
Sales and operations expenses	(282,853)	(229,530)	(176,927)
General and administrative expenses	(117,469)	(79,145)	(64,723)
Total operating expenses	(523,971)	(395,482)	(301,725)
Income from operations	121,004	76,334	53,084
Financial income (expense)	(546)	(4,541)	11,390
Income before taxes	120,458	71,793	64,474
Provision for income taxes	(33,129)	(9,517)	(17,578)
Net income	87,329	62,276	46,896
Net income available to shareholders of Criteo S.A.	82,272	59,553	45,556
Net income available to non-controlling interests	$ 5,057	$ 2,723	$ 1,340
Net income allocated to shareholders per share:
Net income allocated to shareholders per share, Basic (in dollars per share)	$ 1.30	$ 0.96	$ 0.77
Net income allocated to shareholders per share, Diluted (in dollars per share)	$ 1.25	$ 0.91	$ 0.72
Weighted average shares outstanding, basic (in shares)	63,337,792	61,835,499	58,928,563
Weighted average shares outstanding used in computing per share amounts, Diluted (in shares)	65,633,470	65,096,486	63,493,260

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 87,329	$ 62,276	$ 46,896
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation differences, net of taxes	(18,571)	(37,234)	(48,190)
Foreign currency translation differences	(18,571)	(37,234)	(48,190)
Income tax effect	0	0	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]
Actuarial (losses) gains on employee benefits, net of taxes	(1,129)	105	435
Actuarial (losses) gains on employee benefits	(1,335)	127	512
Income tax effect	206	(22)	(77)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Financial instruments, net of taxes	0	0	0
Fair value change on financial instruments	0	0	0
Income tax effect	0	0	0
Comprehensive income (loss)	67,629	25,147	(859)
Attributable to shareholders of Criteo S.A.	62,820	22,418	(1,968)
Attributable to non-controlling interests	$ 4,809	$ 2,729	$ 1,109

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Share capital	Additional paid-in capital	Accumulated other comprehensive (loss) income	Retained earnings	Equity - attributable to shareholders of Criteo S.A.	Non controlling interests
Beginning balance (in shares) at Dec. 31, 2013		56,856,070
Beginning balance at Dec. 31, 2013	$ 365,561	$ 1,873	$ 336,804	$ 15,624	$ 10,967	$ 365,268	$ 293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46,896				45,556	45,556	1,340
Other comprehensive income (loss)	(47,755)			(47,524)		(47,524)	(231)
Issuance of ordinary shares	32,040	$ 135	31,905			32,040
Shared-based compensation	19,601		19,263			19,263	338
Other changes in equity	$ 12			12		12
Ending balance (in shares) at Dec. 31, 2014	60,902,695	60,902,695
Ending balance at Dec. 31, 2014	$ 416,355	$ 2,008	387,972	(31,888)	56,523	414,615	1,740
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	62,276				59,553	59,553	2,723
Other comprehensive income (loss)	(37,129)			(37,135)		(37,135)	6
Issuance of ordinary shares	13,770	$ 44	13,726			13,770
Shared-based compensation	23,989		23,760			23,760	229
Other changes in equity	$ (238)		(238)			(238)
Ending balance (in shares) at Dec. 31, 2015	62,470,881	62,470,881
Ending balance at Dec. 31, 2015	$ 479,023	$ 2,052	425,220	(69,023)	116,076	474,325	4,698
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	87,329				82,272	82,272	5,057
Other comprehensive income (loss)	(19,700)			(19,452)		(19,452)	(248)
Issuance of ordinary shares	21,747	$ 41	21,706			21,747
Shared-based compensation	41,589		41,351			41,351	238
Other changes in equity	$ (111)			(118)	7	(111)
Ending balance (in shares) at Dec. 31, 2016	63,978,204	63,978,204
Ending balance at Dec. 31, 2016	$ 609,877	$ 2,093	$ 488,277	$ (88,593)	$ 198,355	$ 600,132	$ 9,745

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash From (Used in) Operating Activities [Abstract]
Net income		$ 87,329	$ 62,276	$ 46,896
Non-cash and non-operating items [Abstract]
Non-cash and non-operating items		139,122	78,448	71,544
Amortization and provisions		62,733	47,085	33,365
Equity awards compensation expense	[1]	43,259	23,989	19,600
Net gain (or loss) on disposal of non-current assets		(81)	(2,127)	141
Interest accrued and non-cash financial income and expenses		39	28	861
Change in deferred taxes		(10,024)	(15,748)	(5,315)
Income tax for the period		43,196	25,221	22,892
Change in working capital requirement [Abstract]
Change in working capital		(29,460)	15,231	4,661
(Increase) in trade receivables		(117,970)	(83,420)	(83,646)
Increase in trade payables		81,862	100,047	70,557
(Increase) in other current assets		(28,432)	(24,101)	(7,986)
Increase in other current liabilities		35,080	22,705	25,736
Income taxes paid		(43,522)	(18,805)	(6,820)
Cash from operating activities		153,469	137,150	116,281
Cash From (Used in) Investing Activities [Abstract]
Acquisition of intangibles assets, property, plant and equipment		(85,133)	(75,607)	(48,591)
Change in accounts payable related to intangible assets, property, plant and equipment		7,752	1,128	1,705
Payments for acquired businesses, net of cash acquired		(235,541)	(20,542)	(26,103)
Change in other financial non-current assets		159	(6,612)	(2,292)
Cash used to investing activities		(312,763)	(101,633)	(75,281)
Cash From (Used in) Financing Activities [Abstract]
Issuance of long term borrowings		84,022	4,023	5,628
Repayment of borrowings	[2]	(13,305)	(8,980)	(6,525)
Proceeds from capital increase		20,075	13,768	31,638
Change in other financial liabilities		(222)	(1,000)	272
Cash from financing activities		90,570	7,811	31,013
Change in net cash and cash equivalents		(68,724)	43,328	72,013
Net cash and cash equivalents - beginning of period		353,537	351,827	323,181
Effect of exchange rate changes on cash and cash equivalents		(14,496)	(41,618)	(43,367)
Net cash and cash equivalents - end of period		270,317	353,537	351,827
Shared-based compensation expense		41,589	$ 23,743	$ 19,469
Interest paid		$ 1,300
[1]	$41.6 million of equity awards compensation expense consisted of share-based compensation expense according to ASC 718 - Compensation - stock compensation for the year ended December 31, 2016.
[2]	Interest paid for the year ended December 31, 2016 amounted to $1.3 million, and was immaterial for the year ended December 31, 2015 and 2014.

Principles and Accounting Metho

Principles and Accounting Methods	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Principles and Accounting Methods	Criteo S.A. was initially incorporated as a société par actions simplifiée, or S.A.S., under the laws of the French Republic on November 3, 2005, for a period of 99 years and subsequently converted to a société anonyme, or S.A. Criteo S.A. is a global technology company specialized in digital performance marketing. We strive to deliver post-click sales to our advertiser clients at scale across multiple digital marketing channels, and according to the client's targeted return on investment. In these notes, Criteo S.A. is referred to as the Parent company and together with its subsidiaries, collectively, as "Criteo," the "Company," the "Group," or "we". The Company uses its proprietary machine-learning algorithms, coupled with large volumes of granular shopping intent data and deep insights into consumer intent and purchasing habits, to price and deliver in real time highly relevant and personalized digital performance advertisements to consumers. Principles and Accounting Methods Basis of Preparation The Consolidated Financial Statements have been prepared assuming a going concern and using the historical cost principle with the exception of certain assets and liabilities that are measured at fair value in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The categories concerned are detailed in the following notes. Consolidation Methods We have control over all our subsidiaries, and consequently they are all fully consolidated. Intercompany transactions and balances have been eliminated. The table below presents at each period’s end and for all entities included in the consolidation scope the following information: the country of incorporation and the percentage of voting rights and ownership interests. 2015 2016 Country Voting rights Ownership Interest Voting rights Ownership Interest Consolidation Method Parent company Criteo S.A France 100 % 100 % 100 % 100 % Parent company French subsidiaries Criteo France SAS France 100 % 100 % 100 % 100 % Fully consolidated Criteo Finance SAS France - - 100 % 100 % Fully consolidated Foreign subsidiaries Criteo Ltd United Kingdom 100 % 100 % 100 % 100 % Fully consolidated Criteo Corp United States 100 % 100 % 100 % 100 % Fully consolidated Criteo Gmbh Germany 100 % 100 % 100 % 100 % Fully consolidated Criteo KK Japan 66 % 66 % 66 % 66 % Fully consolidated Criteo Do Brasil LTDA Brazil 100 % 100 % 100 % 100 % Fully consolidated Criteo BV The Netherlands 100 % 100 % 100 % 100 % Fully consolidated Criteo Pty Australia 100 % 100 % 100 % 100 % Fully consolidated Criteo Srl Italy 100 % 100 % 100 % 100 % Fully consolidated Criteo Advertising (Beijng) Co. Ltd China 100 % 100 % 100 % 100 % Fully consolidated Criteo Singapore Pte. Ltd. Singapore 100 % 100 % 100 % 100 % Fully consolidated Criteo LLC Russia 100 % 100 % 100 % 100 % Fully consolidated Criteo Europa S.L. Spain 100 % 100 % 100 % 100 % Fully consolidated Criteo Espana S.L. Spain 100 % 100 % 100 % 100 % Fully consolidated Criteo Canada Corp. Canada 100 % 100 % 100 % 100 % Fully consolidated Criteo Reklamcılık Hizmetleri ve Ticaret Anonim Şirketi Turkey 100 % 100 % 100 % 100 % Fully consolidated Criteo MEA FZ-LLC United Arab Emirates 100 % 100 % 100 % 100 % Fully consolidated Criteo India Private Ltd. India - - 100 % 100 % Fully consolidated HookLogic, Inc. United States - - 100 % 100 % Fully consolidated HookLogic Ltd United Kingdom - - 100 % 100 % Fully consolidated Hooklogic Brasil Solucoes EM Tecnología Ltda Brazil - - 100 % 100 % Fully consolidated Functional Currency and Translation of Financial Statements in Foreign Currency The Consolidated Financial Statements are presented in U.S. dollars, which differs from the functional currency of the Parent, being the Euro. The statements of financial position of consolidated entities having a functional currency different from the U.S. dollar are translated into U.S. dollars at the closing exchange rate (spot exchange rate at the statement of financial position date) and the statements of income, statements of comprehensive income and statements of cash flow of such consolidated entities are translated at the average period to date exchange rate. The resulting translation adjustments are included in equity under the caption “Accumulated other comprehensive income (loss)” in the Consolidated Statements of Changes in Shareholders' Equity. Conversion of Foreign Currency Transactions Foreign currency transactions are converted to U.S. dollars at the rate of exchange applicable on the transaction date. At period-end, foreign currency monetary assets and liabilities are converted at the rate of exchange prevailing on that date. The resulting exchange gains or losses are recorded in the Consolidated Statements of Income in “Other financial income (expense)” with the exception of exchange differences arising from monetary items that form part of the reporting entity’s net investment in a foreign operation which are recognized in other comprehensive income (loss); they will be recognized in profit or loss on disposal of the net investment. Use of Estimates Our Consolidated Financial Statements are prepared in accordance with U.S. GAAP. The preparation of our Consolidated Financial Statements requires us to make estimates, assumptions and judgments that affect the reported amounts of assets, liabilities, revenue and expenses. We base our estimates and assumptions on historical experience and other factors that we believe to be reasonable under the circumstances. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates. The most significant areas that require management judgment and estimates relate to (1) the recognition of revenue and particularly, the determination as to whether revenue should be reported on a gross or a net basis; (2) the evaluation of our trade receivables and the recognition of a valuation allowance for doubtful accounts; (3) the recognition of our deferred tax assets considering the subsidiaries projected taxable profit within the next three years and the potential tax deduction upon future exercises of share-options in certain jurisdictions; (4) the recognition and measurement of goodwill and intangible assets and particularly costs capitalized in relation to our customized internal-use software; and (5) the measurement of share-based compensation. Business combinations We include the results of operations of the businesses that we acquire as of the acquisition date. We allocate the purchase price of our acquisitions to the assets acquired and liabilities assumed based on their estimated fair values. The excess of the purchase price over the fair values of these identifiable assets and liabilities is recorded as goodwill. Acquisition-related expenses are recognized separately from the business combination and are expensed as incurred. Intangible Assets Acquired intangible assets are accounted for at acquisition cost, less accumulated amortization. Acquired intangible assets are primarily composed of software amortized on a straight-line basis over their estimated useful lives comprised between one and three years. Intangible assets are reviewed for impairment whenever events or changes in circumstances such as, but not limited to, significant declines in revenue, earnings or cash flows or material adverse changes in the business climate indicate that the carrying amount of an asset may be impaired. Costs related to customized internal-use software that have reached the development stage are capitalized. Capitalization of such costs begins when the preliminary project stage is complete and stops when the project is substantially complete and is ready for its intended purpose. In making this determination, several analyses for each phase were performed, including analysis of the feasibility, availability of resources, intention to use and future economic benefits. Amortization of these costs begins when assets are placed in service and is calculated on a straight-line basis over the assets’ useful lives estimated at three to five years. Our research and development efforts are focused on enhancing the performance of our solution and improving the efficiency of the services we deliver to our clients. All development costs, principally headcount-related costs, are expensed as incurred as management has determined that technological feasibility is reached shortly before our product is available for release to customers. Property, Plant and Equipment Property, plant and equipment are accounted for at acquisition cost less cumulative depreciation and any impairment loss. Depreciation is calculated on a straight-line basis over the assets’ estimated useful lives as follows: Fixtures and fittings (mainly composed of leasehold improvements).................................. 5 to 10 years Furniture and equipment (servers and IT equipment in data centers and office equipment)............ 1 to 5 years Leasehold improvements are depreciated over their useful life or over the lease term, whichever is shorter. The gains and losses on disposal of assets are determined by comparing selling price with the net book value of the disposed asset. Impairment of Assets Goodwill and Intangible Assets Goodwill represents the excess of the aggregate purchase price paid over the fair value of the net tangible and intangible assets acquired. Intangible assets that are not considered to have an indefinite useful life are amortized over their useful lives. The Company evaluates the estimated remaining useful lives of purchased intangible assets and whether events or changes in circumstances warrant a revision to the remaining periods of amortization. Goodwill is not amortized and is tested for impairment at least annually or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that it operates as a single reporting unit and has selected December 31 as the date to perform its annual impairment test. In the impairment assessment of its goodwill, the Company performs a two-step impairment test, which involves assumptions regarding estimated future cash flows to be derived from the Company. If these estimates or their related assumptions change in the future, the Company may be required to record impairment for these assets. The first step of the impairment test involves comparing the fair value of the reporting unit to its net book value, including goodwill. If the net book value exceeds its fair value, then the Company would perform the second step of the goodwill impairment test to determine the amount of the impairment loss. The impairment loss to be recognized would be calculated by comparing the implied fair value of the Company to its net book value. In calculating the implied fair value of the Company’s goodwill, the fair value of the Company would be allocated to all of the other assets and liabilities based on their fair values. The excess of the fair value of the Company over the amount assigned to its other assets and liabilities is the implied fair value of goodwill. An impairment loss would be recognized in the Consolidated Statement of Income when the carrying amount of goodwill exceeds its implied fair value. With respect to intangible assets, acquired intangible assets are accounted for at acquisition cost less cumulative amortization and any impairment loss. Acquired intangible assets are amortized over their estimated useful lives of one to five years on a straight-line method. Intangible assets are reviewed for impairment whenever events or changes in circumstances such as, but not limited to, significant declines in revenue, earnings or cash flows or material adverse changes in the financial and economic environment indicate that the carrying amount of an asset may be impaired. Property, Plant and Equipment and Impairment of Long-lived Assets The Company periodically reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful life is no longer appropriate. If indicators of impairment exist and the undiscounted projected cash flows associated with an asset are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. Fair value is estimated based on discounted future cash flows. Leases The Company leases various facilities under agreements accounted for as operating leases. For leases that contain escalation or rent concessions provisions, management recognizes rent expense during the lease term on a straight-line basis over the term of the lease. The difference between rent paid and straight-line rent expense is recorded as a deferred rent liability in the accompanying Consolidated Statement of Financial Position. Assets held under capital leases are recorded at the lower of the net present value of the minimum lease payments or at the fair value of the leased asset at the inception of the lease. Amortization expense is computed using the straight-line method over the shorter of the estimated useful life of the asset or the period of the related lease. Principal payments on capital lease obligations are recorded as reduction of capital lease liability in the accompanying consolidated balance sheets, and interest payments are recorded as interest expense which is included in financial income (expense), in the accompanying Consolidated Statements of Operations. Financial Assets and Liabilities, Excluding Derivative Financial Instruments Financial assets, excluding cash and cash equivalents, consist exclusively of loans and receivables. Loans and receivables are non-derivative financial assets with a payment, which is fixed or can be determined, not listed on an active market. They are included in current assets, except those that mature more than twelve months after the reporting date. Loans are measured at amortized cost using the effective interest method. The recoverable amount of loans and advances is estimated whenever there is an indication that the asset may be impaired and at least on each reporting date. If the recoverable amount is lower than the carrying amount, an impairment loss is recognized in the Consolidated Statements of Income. Financial liabilities are initially recorded at their fair value at the transaction date. Subsequently they are measured at amortized cost using the effective interest method. We carry our accounts receivable at net realizable value. On a periodic basis, our management evaluates our accounts receivable and determines whether to provide an allowance or if any accounts should be written down and charged to expense as a bad debt. The evaluation is based on, among other factors, a past history of collections, current credit conditions, the ageing of the receivable and a past history of write downs. A receivable is considered past due if we have not received payments based on agreed-upon terms. A higher default rate than estimated or a deterioration in our clients’ creditworthiness could have an adverse impact on our future results. Allowances for doubtful accounts on trade receivables are recorded in “sales and operations expenses” in our Consolidated Statements of Income. We generally do not require any security or collateral to support our receivables. Derivative financial instruments We buy and sell derivative financial instruments (mainly put, forward buying and selling) in order to manage and reduce our exposure to the risk of exchange rate fluctuations. We deal only with major financial institutions. Under the ASC 815 – Derivatives and hedging , financial instruments may only be classified as hedges when we can demonstrate and document the effectiveness of the hedging relationship at inception and throughout the life of the hedge. The effectiveness of the hedge is determined by reference to changes in the value of the derivative instrument and the hedged item. The ratio must remain within 80% to 125% . Derivative financial instruments are recognized in the balance sheet at their market value on the reporting date in financial current assets or liabilities. Changes in fair value are recorded as follows: • cash flow hedges : the portion of the gain or loss on the financial instrument that is determined to be an effective hedge is recorded directly to equity. The ineffective portion is recorded to the income statement; • fair value hedges and financial instruments not designated as hedges : changes in fair value are recorded to the income statement. Fair value measurements In accordance with ASC 820 – Fair value measurement , financial instruments are presented in three categories based on a hierarchical method used to determine their fair value : (i) level 1: fair value calculated using quoted prices in an active market for identical assets and liabilities; (ii) level 2: fair value calculated using valuation techniques based on observable market data such as prices of similar assets and liabilities or parameters quoted in an active market; (iii) level 3: fair value calculated using valuation techniques based wholly or partially on unobservable inputs such as prices in an active market or a valuation based on multiples for unlisted companies. The Company's valuation techniques used to measure the fair value of money market funds and certain short term investments were derived from quoted prices in active markets. The valuation techniques used to measure the fair value of the Company's financial liabilities and all other financial instruments, all of which have counterparties with high credit ratings, were valued based on quoted market prices or model-driven valuations using inputs derived from or corroborated by observable market data. Cash and Cash Equivalents Cash includes cash on hand and demand deposits with banks. Cash equivalents include short-term, highly liquid investments, with a remaining maturity at the date of purchase of three months or less for which the risk of changes in value is considered to be insignificant. Demand deposits therefore meet the definition of cash equivalents. Cash equivalents are measured at fair value using level 1 for cash at hand and money market funds using quoted prices, and any changes are recognized in the Consolidated Statements of Income. Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and accounts receivable. The Company’s cash and cash equivalents are held at major financial institutions that the Company's management has assessed to be of high credit quality. The Company has not experienced any losses in such accounts. The Company mitigates its credit risk with respect to accounts receivable by performing credit evaluations and monitoring agencies' and advertisers' accounts receivable balances. As of December 31, 2016 and 2015 no customer accounted for 10% or more of accounts receivable. During the years ended December 31, 2016 , 2015 and 2014 , no single customer represented 10% or more of revenue. Employee Benefits Depending on the laws and practices of the countries in which we operate, employees may be entitled to compensation when they retire or to a pension following their retirement. For state-managed plans and other defined contribution plans, we recognize them as expenses when they become payable, our commitment being limited to our contributions. The liability with respect to defined benefit plans is estimated using the following main assumptions: • discount rate; • future salary increases; and • employee turnover. Service costs are recognized in profit or loss and are allocated by function. Actuarial gains and losses are recognized in other comprehensive income and subsequently amortized into the income statement over a specified period, which is generally the expected average remaining service period of the employees participating in the plan. Actuarial gains and losses arise as a result of changes in actuarial assumptions or experience adjustments (differences between the previous actuarial assumptions and what has actually occurred). Contingencies We recognize contingencies in accordance with ASC 450 - Contingencies , if the following two conditions are met: • information available before the financial statements are issued indicates that it is probable that an asset had been impaired or a liability had been incurred at the date of the financial statements; • the amount of loss can be reasonably estimated With respect to litigation and claims that may result in a provision to be recognized, we exercise significant judgment in measuring and recognizing provisions or determining exposure to contingent liabilities that are related to pending litigation or other outstanding claims. These judgment and estimates are subject to change as new information becomes available. Revenue Recognition We sell personalized display advertisements featuring product-level recommendations either directly to clients or to advertising agencies, which we collectively refer to as our clients, and generate revenue when a user clicks on the banner ad. We generally price our advertising campaigns on a cost per click (“CPC”) model based on the number of clicks generated by users on each advertisement we deliver in our advertising campaigns. Revenue is recognized when the related services are delivered based on the specific terms of the contract, which are commonly based on specified CPCs and related campaign budgets. We recognize revenue when four basic criteria are met: (1) persuasive evidence exists of an arrangement with the client reflecting the terms and conditions under which the services will be provided; (2) services have been provided or delivery has occurred; (3) the fee is fixed or determinable; and (4) collection is reasonably assured. Collectability is assessed based on a number of factors, including the creditworthiness of a client, the size and nature of a client’s website and transaction history. Amounts billed or collected in excess of revenue recognized are included as deferred revenue. An example of this deferred revenue would be arrangements where clients request or are required by us to pay in advance of delivery. We recognize revenue from the delivery of display advertisements in the period in which the display advertisements are delivered. Specifically, we recognize revenue for display ad delivery through our solution once the consumer clicks on the personalized banner displayed by us on the client’s website for CPC ad campaigns. For CPC ad campaigns, sales are valued at the fair value of the amount received. Rebates and discounts granted to clients, along with free or extended advertising campaigns, are recorded as a deduction from revenue. Essentially all of our revenue in each of 2014 , 2015 and 2016 was derived from advertising campaigns sold on a CPC basis. In the specific case of Criteo Predictive Search, we recognize revenue when users exposed to the Google Shopping campaigns of our clients generate a sale on the digital property of our clients after clicking on the shopping advertisements displayed on Google. Our revenue for Criteo Predictive Search is a percentage of the sales generated by a client's Google Shopping campaigns, which means we only get paid for completed sales. The determination of whether revenue should be reported on a gross or net basis is based on an assessment of whether we are acting as the principal or an agent in our transactions. In determining whether we act as the principal or an agent, we follow the accounting guidance for principal-agent considerations. The determination of whether we are acting as a principal or an agent in a transaction involves judgment and is based on an evaluation of the terms of each arrangement. While none of the factors individually are considered presumptive or determinative, because we are the primary obligor and are responsible for (1) identifying and contracting with third-party clients; (2) establishing the selling prices of the display advertisements sold; (3) performing all billing and collection activities, including retaining credit risk; and (4) bearing sole responsibility for fulfillment of the advertising and the inventory risk, we act as the principal in these arrangements and therefore report revenue earned and costs incurred related to these transactions on a gross basis. With Criteo Predictive Search, we do not purchase search inventory ourselves; our advertiser clients have direct access to Google Shopping inventory and buy such inventory themselves. As a result of not incurring inventory costs related to these transactions, we act as an agent for our clients with respect to these transactions. Consequently, revenue for Criteo Predictive Search is reported on a net basis. In the specific case of Criteo Sponsored Products, we generally act as principal and as a result, we report revenue earned and costs incurred related to these transactions on a gross basis. When we do not (i) set the price, (ii) select the publisher site the advertisement is placed on, (iii) take responsibility for the acceptability of the service and (iv) bear the credit risk, we report revenue earned and costs incurred related to these transactions on a net basis. Cost of Revenue Our cost of revenue primarily includes traffic acquisition costs and other cost of revenue. Traffic Acquisition Costs . Traffic acquisition costs consist primarily of purchases of impressions from publishers on a CPM basis. We purchase impressions directly from publishers or third-party intermediaries, such as advertisement exchanges. We recognize cost of revenue on a publisher by publisher basis as incurred. Costs owed to publishers but not yet paid are recorded in our Consolidated Statements of Financial Position as trade payables and other current liabilities. Under our current agreements with our publishers, we only commit to purchase a defined volume of impressions from any given publisher to the extent that a pre-determined click through rate, or CTR, is reached. If the publisher fails to reach the targeted volume of impressions, we can either terminate the agreement or reduce our commitment to buy impressions accordingly. For Criteo Sponsored Products, we pay for the inventory of our ecommerce retailer partners on a revenue sharing basis, effectively paying the retailers a portion of the click-based revenue generated by user clicks on the sponsored products advertisements displaying the products of our brand manufacturer clients. For Criteo Predictive Search, we do not purchase search inventory ourselves; our advertiser clients have direct access to Google Shopping inventory, and we optimize the bidding price for such inventory on behalf of the clients to maximize the sales generated by shopping campaigns. Other Cost of Revenue . Other cost of revenue includes expenses related to third-party hosting fees, depreciation of data center equipment and data purchased from third parties. The Company does not build or operate its own data centers and none of its Research and Development employments are dedicated to revenue generating activities. As a result, we do not include the costs of such personnel in other cost of revenue. Share-Based Compensation Shares, employee share options and employee and non-employee warrants are primarily awarded to our employees or directors. As required by ASC 718 – Compensation – Stock Compensation , these awards are measured at their fair value on the date of grant. The fair value is calculated with the most relevant formula regarding the settlement and the conditions of each plan. The fair value is recorded in personnel expenses (allocated by function in the Consolidated Statements of Income) on a straight-line basis over each milestone composing the vesting period with a corresponding increase in shareholders’ equity. At each closing date, we re-examine the number of options likely to become exercisable. If applicable, the impact of the review of the estimate is recognized in the Consolidated Statements of Income with a corresponding adjustment in equity. Income Taxes We elected to classify the French business tax, Cotisation sur la Valeur Ajoutée des Entreprises (“CVAE”), as an income tax in compliance with ASC 740— Income Taxes (“ASC 740”). The French Research Tax Credit, Crédit d’Impôt Recherche (“CIR”), is a French tax incentive to stimulate research and development (“R&D”). Generally, the CIR offsets the income tax to be paid and the remaining portion (if any) can be refunded at the end of a three-fiscal year period. The CIR is calculated based on the claimed volume of eligible R&D expenditures by us. As a result, the CIR is presented as a deduction to “research and development expenses” in the Consolidated Statements of Income, as the CIR is not within the scope of ASC 740. We have exclusively claimed R&D performed in France for purposes of the CIR. Income taxes are accounted for under the asset and liability method of accounting. Deferred taxes are recorded on all temporary differences between the financial reporting and tax bases of assets and liabilities, and on tax losses, using the liability method. Differences are defined as temporary when they are expected to reverse within a foreseeable future. We may only recognize deferred tax assets if, based on the projected taxable incomes within the next three years, we determine that it is probable that future taxable profit will be available against which the unused tax losses and tax credits can be utilized. As a result, the measurement of deferred income tax assets is reduced, if necessary, by a valuation allowance for any tax benefits which are not expected to be realized. If future taxable profits are considerably different from those forecasted that support recording deferred tax assets, we will have to revise downwards or upwards the amount of deferred tax assets, which would have a significant impact on our financial results. This determination requires many estimates and judgments by our management for which the ultimate tax determination may be uncertain. In accordance with ASC 740, tax assets and liabilities are not discounted. Amounts recognized in the Consolidated Financial Statements are calculated at the level of each tax entity included in the consolidation scope. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in the period that such tax rate changes are enacted. Uncertain Tax Positions The Company follows the guidance of ASC 740, which prescribes a more likely than not threshold for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. This Interpretation also provides guidance on recognition of income tax assets and liabilities, classification of current and deferred income tax assets and liabilities, accounting for interest and penalties associated with tax positions, accounting for income taxes in interim periods, and income tax disclosures. Operating Segments In accordance with ASC 280 – Segment reporting , segment information reported is built on the basis of internal management data used for performance analysis of businesses and for the allocation of resources (management approach). An operating segment is a component of the Company for which separate financial information is available that is evaluated regularly by our Chief Decision Maker in deciding how to allocate resources and assessing performance. Our chief operating decision-maker is our CEO. The CEO reviews consolidated data for revenue, revenue excluding traffic acquisition costs (revenue ex-TAC) and Adjusted EBITDA (earnings before financial income (expense), income taxes, depreciation and amortization, adjusted to eliminate the impact of equity awards compensation expense, pension service costs, acquisition-related costs and deferred price consideration ) for the purposes of allocating resources and evaluating financial performance. We have concluded that our operations constitute one operating and reportable segment. Earnings Per Share In accordance with ASC 260— Earnings Per Share , basic earnings per share (“EPS”) are calculated by dividing the net income attributable to shareholders of the Parent by the weighted average number of shares outstanding. The weighted average number of shares outstanding is calculated according to movements in share capital. In addition, we calculate diluted earnings per share by dividing

Significant Events and Transact

Significant Events and Transactions of the Period	12 Months Ended
	Dec. 31, 2016
Significant Events and Transactions of the Period Disclosure [Abstract]
Significant Events and Transactions of the Period	Significant Events and Transactions of the Period Changes in the scope of consolidation Business combinations HookLogic Inc. On November 9, 2016, we completed the acquisition of all of the outstanding shares of Hooklogic, Inc. ("HookLogic"). Please refer to Note 3 for further details. Monsieur Drive Acquisition On May 31, 2016, we acquired all of the outstanding shares of Monsieur Drive SAS. ("Monsieur Drive"), a Paris-based company building advertising products for the consumer packaged goods vertical. Please refer to Note 3 for further details. Consolidation scope Creation of Criteo India Pvt Ltd (India) This new subsidiary is 100% held and controlled by the Parent Company. It is included in the Company’s consolidation scope as of December 31, 2016 , but its contribution to the Consolidated Financial Statements is not material. Creation of Criteo Finance SAS (France) This new subsidiary is 100% held and controlled by the Parent company. It is included in the Company’s consolidation scope as of December 31, 2016, but its contribution to the Consolidated Financial Statements is not material. The business objective of this subsidiary is to enhance the service level to strategic global customers by providing them with one single billing relationship and to consolidate the management of the foreign exchange risk. Changes in Group funding Drawing on Group Revolving Credit Facility In September 2015, Criteo S.A. entered into a Multicurrency Revolving Facility Agreement for general purposes of the Group including the funding of business combinations. In the context of the acquisition of HookLogic Inc., $75.0 million was drawn in November 2016. Drawing on Chinese revolving loan facility In October 2014, we entered into a revolving loan facility with HSBC to support the development of our Chinese subsidiary for a total amount of RMB15.0 million . This facility was increased to RMB 40.0 million in May 2015. At December 31, 2015 and 2016, RMB 25 million ( $3.9 million ) and RMB 30.0 million ( $4.3 million ) was drawn.

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Combination	Business combination Acquisition of HookLogic Inc. On November 9, 2016, we completed the acquisition of all of the outstanding shares of Hooklogic, a New York-based company connecting many of the world's largest ecommerce retailers with consumer brand manufacturers. The total consideration paid was $250.1 million for the acquisition of shares. The acquisition was financed by (i) a $75.0 million amount drawn on the Revolving Credit Facility entered into in September 2015 and (ii) $175.1 million financed by available cash resources. The purchase price allocation is in progress. A preliminary valuation of the fair value of HookLogic's assets acquired and liabilities assumed has been performed as of December 31, 2016. Provisional goodwill amounted to $165.3 million , subject to post-closing working capital adjustments. Once this valuation analysis is finalized, the estimate of the fair value of the assets acquired and liabilities assumed may be adjusted. Several factors gave rise to the provisional goodwill recorded in the acquisition, such as the expected benefits of the addition of HookLogic to the existing performance marketing platform of the Company. Goodwill is not expected to be deductible for tax purposes. In addition, acquisition costs amounting to $2.2 million were fully expensed as incurred. The transaction has been accounted for as a business combination under the acquisition method of accounting. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed as of the acquisition date. Due to the timing of the acquisition, these amounts are provisional and subject to change. The Company will finalize these amounts as it obtains the information necessary to complete the measurement process. Any changes resulting from facts and circumstances that existed as of the acquisition date may result in adjustments to the provisional amounts recognized at the acquisition date. These changes could be significant. The Company will finalize these amounts no later than one year from the acquisition date. In allocating the purchase price for the transaction, the Company recorded the following (in millions): Amounts recognized as of Acquisition Date (in millions) Cash and cash equivalents $ 19.7 Trade receivables, net of allowances 29.2 Other current assets 1.0 Property, plant and equipment, net 1.3 Identifiable intangible assets 84.4 Non-current financial assets 0.3 Trade payables (38.7 ) Financial liabilities - current portion (7.4 ) Other taxes (0.5 ) Employee-related payables (1.4 ) Other current liabilities (3.1 ) Total identifiable net assets 84.8 Goodwill 165.3 Total fair value of consideration transferred $ 250.1 The following table summarizes the amounts and useful lives assigned to identified intangible assets : Weighted-Average Useful Lives (Years) Amounts recognized as of Acquisition Date (in millions) Technology 3-5 years 24.4 Customer relationships 5-9 years $ 60.0 Total identifiable intangible assets acquired $ 84.4 Assuming a weighted-average useful life of 4 years and 7 years for technology and customer relationships, respectively, annual expected amortization expense would amount to $6.0 million and $8.6 million , respectively. The contribution of HookLogic to revenue, revenue ex-TAC and net income included in the Consolidated Financial Statements from the acquisition date to December 31, 2016 were $45.2 million , $12.3 million and $2.7 million , respectively. The following unaudited consolidated revenue, revenue ex-TAC and net income from the standalone financial statements of HookLogic prepared under U.S. GAAP for the year ended December 31, 2016 amounts to $116.7 million , $34.1 million and $(4.8) million , respectively. Acquisition of Monsieur Drive On May 31, 2016, we acquired all of the outstanding shares of Monsieur Drive. The total consideration paid was $5.1 million ( €4.6 million ) for the acquisition of the shares, financed by available cash resources at the acquisition date. A preliminary valuation of the fair value of Monsieur Drive's assets acquired, liabilities assumed and the related allocation of purchase price has been performed as of December 31, 2016, resulting in the identification of a technology asset of $1.2 million ( €1.2 million ) and related deferred tax liability of $0.2 million ( €0.2 million ). Provisional goodwill amounted to $3.7 million ( €3.5 million ). Once this valuation analysis is finalized, the estimate of the fair value of the assets acquired and liabilities assumed may be adjusted. In addition, acquisition costs amounting to $0.2 million ( €0.2 million ) were fully expensed as incurred.

Categories of Financial Assets

Categories of Financial Assets and Financial Liabilities	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Categories of Financial Assets and Financial Liabilities	Categories of Financial Assets and Financial Liabilities Financial Assets The following schedules disclose our financial assets categories for the presented periods: Year Ended December 31, 2015 Carrying Value Loans and receivables Fair value (in thousands) Cash and cash equivalents $ 353,537 $ — $ 353,537 Trade receivables, net of allowances 261,581 261,581 $ 261,581 Other taxes 29,552 29,552 $ 29,552 Other current assets 16,030 16,030 $ 16,030 Financial assets 17,184 17,184 $ 17,184 Total $ 677,884 $ 324,347 $ 677,884 Year Ended December 31, 2016 Carrying Value Loans and receivables Fair value (in thousands) Cash and cash equivalents $ 270,317 $ — $ 270,317 Trade receivables, net of allowances 397,244 397,244 $ 397,244 Other taxes 52,942 52,942 $ 52,942 Other current assets 19,340 19,340 $ 19,340 Financial assets 17,029 17,029 $ 17,029 Total $ 756,872 $ 486,555 $ 756,872 Credit Risk The maximum exposure to credit risk at the end of each reported period is represented by the carrying amount of financial assets, and summarized in the following table: Year Ended December 31, 2015 2016 (in thousands) Cash and cash equivalents $ 353,537 $ 270,317 Trade receivables, net of allowances 261,581 397,244 Other taxes 29,552 52,942 Other current assets 16,030 19,340 Non-current financial assets 17,184 17,029 Total $ 677,884 $ 756,872 As of December 31, 2016 and 2015 , no customer accounted for 10% or more of trade receivables. We perform ongoing credit evaluations of our customers and do not require collateral. We maintain an allowance for estimated credit losses. During the years ended December 31, 2016 and 2015 , our net change in allowance for doubtful accounts was $5.4 million and $2.3 million , respectively. Trade Receivables Credit risk is defined as an unexpected loss in cash and earnings if the client is unable to pay its obligations in due time. We perform internal ongoing credit risk evaluations of our clients. When a possible risk exposure is identified, we require prepayments. For each period presented, the aging of trade receivables and allowances for doubtful accounts is as follows: Year Ended December 31, 2015 2016 Gross value % Allowance % Gross value % Allowance % (in thousands) (in thousands) (in thousands) (in thousands) Not yet due $ 193,603 72.2 % $ — — % $ 265,600 65.0 % $ — — % 0 - 30 days $ 53,803 20.1 % $ — — % $ 92,163 22.5 % $ (49 ) 0.4 % 31 - 60 days $ 8,287 3.1 % $ — — % $ 19,747 4.8 % $ (182 ) 1.6 % 61 - 90 days $ 2,574 1.0 % $ (2 ) — % $ 6,055 1.5 % $ (191 ) 1.6 % > 90 days $ 9,578 3.6 % $ (6,262 ) 100.0 % $ 25,277 6.2 % $ (11,176 ) 96.4 % Total $ 267,845 100.0 % $ (6,264 ) 100.0 % $ 408,842 100.0 % $ (11,598 ) 100.0 % Cash and Cash Equivalents Cash and cash equivalents are exclusively invested in secure investments such as interest-bearing term deposits. Financial Liabilities Year Ended December 31, 2015 Carrying Value Fair value (in thousands) Trade payables $ 246,382 $ 246,382 Other taxes 30,463 30,463 Employee - related payables 42,275 42,275 Other current liabilities 15,531 15,531 Financial liabilities 10,428 10,428 of which derivative financial instruments 553 553 Total $ 345,079 $ 345,079 Year Ended December 31, 2016 Carrying Value Fair value (in thousands) Trade payables $ 365,788 $ 365,788 Other taxes 44,831 44,831 Employee - related payables 55,874 55,874 Other current liabilities 30,221 30,221 Financial liabilities 85,580 85,580 of which derivative financial instruments 1,968 $ 1,968 Total $ 582,294 $ 582,294 Fair Value Measurements We measure the fair value of our cash equivalents, which include money market funds and interest bearing deposits, as level 1 and level 2 measurements because they are valued using quoted market prices and observable market data, respectively. Financial liabilities include derivative financial instruments used to manage our exposure to the risk of exchange rate fluctuations. These instruments are considered level 2 financial instruments as they are measured using valuation techniques based on observable market data.

Cash and Cash Equivalents

Cash and Cash Equivalents	12 Months Ended
	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents Disclosure [Text Block]	Cash and Cash Equivalents The following table presents for each reported period, the breakdown of cash and cash equivalents: Year Ended December 31, 2015 2016 (in thousands) Money market funds $ 54,188 $ 31,688 Interest-bearing bank deposits 114,127 88,091 Cash and cash equivalents 185,222 150,538 Total Cash and cash equivalents $ 353,537 $ 270,317 The short-term investments included investments in money market funds and interest–bearing bank deposits which met ASC 230— Statement of Cash flows criteria: short-term, highly liquid investments, for which the risks of changes in value are considered to be insignificant. The following table shows the allocation by currency of our financial liabilities and cash and cash equivalents: Currency Carrying value EUR GBP USD CNY JPY KRW Other (in thousands) Borrowings $ 82,921 $ 3,289 $ — $ 75,253 $ 4,379 $ — $ — $ — Other financial liabilities 691 450 — 241 — — — — Financial derivatives 1,968 1,968 — — — — — — Financial liabilities 85,580 5,707 — 75,494 4,379 — — — Cash and cash equivalents $ 270,317 $ 197,997 $ 2,887 $ 29,636 $ 3,074 $ 17,316 $ 2,531 $ 16,876

Trade Receivables

Trade Receivables	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Trade Receivables	Trade Receivables The following table shows the breakdown in trade receivables net book value for the presented periods: Year Ended December 31, 2015 2016 (in thousands) Trade accounts receivables $ 267,845 $ 408,842 (Less) Allowance for doubtful accounts (6,264 ) (11,598 ) Net book value at end of period $ 261,581 $ 397,244 Changes in allowance for doubtful accounts are summarized below: Year Ended December 31, 2014 2015 2016 (in thousands) Balance at beginning of period $ (2,529 ) $ (3,930 ) $ (6,264 ) Provision for doubtful accounts (2,248 ) (2,660 ) (9,898 ) Reversal of provision 910 — 4,464 Change in consolidation scope (450 ) (99 ) (221 ) Currency translation adjustment 387 425 321 Balance at end of period $ (3,930 ) $ (6,264 ) $ (11,598 )

Other Current Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Current Assets	Other Current Assets The following table shows the breakdown in other current assets net book value for the presented periods: Year Ended December 31, 2015 2016 (in thousands) Prepayments to suppliers $ 2,774 $ 2,439 Employee-related receivables 94 97 Taxes receivables 29,552 52,942 Other debtors 3,687 3,166 Prepaid expenses 9,475 13,638 Gross book value at end of period 45,582 72,282 Net book value at end of period $ 45,582 $ 72,282 Taxes receivables are primarily composed of VAT receivables and research tax credit receivables. Prepaid expenses mainly consist of office rental advance payments.

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Changes in net book value during the presented periods are summarized below: Fixtures and fittings Furniture and equipment Construction in Progress Total (in thousands) Net book value at January 1, 2015 $ 2,501 $ 47,391 $ 2,347 $ 52,239 Additions to tangible assets 13,408 50,849 3,990 68,247 Disposal of tangible assets (53 ) (48 ) — (101 ) Depreciation expense (1,840 ) (32,487 ) — (34,327 ) Change in consolidation scope 31 87 — 118 Currency translation adjustment (488 ) (2,936 ) (270 ) (3,694 ) Transfer into service 784 677 (1,461 ) — Net book value at December 31, 2015 14,343 63,533 4,606 82,482 Gross book value at end of period 15,948 125,968 4,606 146,522 Accumulated depreciation and impairment at end of period (1,605 ) (62,435 ) — (64,040 ) Net book value at January 1, 2016 14,343 63,533 4,606 82,482 Additions to tangible assets 6,188 57,866 11,976 76,030 Disposal of tangible assets net of accumulated depreciation — (8 ) — (8 ) Depreciation expense (4,496 ) (43,665 ) — (48,161 ) Change in consolidation scope 85 405 — 490 Currency translation adjustment (499 ) (1,665 ) (88 ) (2,252 ) Transfer into service 2,544 1,283 (3,827 ) — Net book value at December 31, 2016 $ 18,165 $ 77,749 $ 12,667 $ 108,581 Gross book value at end of period 24,200 179,025 12,667 215,892 Accumulated depreciation and impairment at end of period (6,035 ) (101,276 ) — (107,311 ) The increase in property plant and equipment (gross book value and accumulated depreciation) mainly includes server equipment in the French, American and Japanese subsidiaries where the Company’s data center equipments are located as well as fit out of new office locations in the United States and Singapore.

Intangible assets

Intangible assets	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets	Intangible assets Changes in net book value during the presented periods are summarized below: Software Technology and customer relationships Construction in Progress Total (in thousands) Net book value at January 1, 2015 $ 5,122 $ 7,356 $ 343 $ 12,821 Additions to intangible assets 5,645 554 1,172 7,371 Amortization expense (3,631 ) (6,604 ) — (10,235 ) Change in consolidation scope 1 7,800 — 7,801 Currency translation adjustment (570 ) (666 ) (52 ) (1,288 ) Transfer into service 314 — (314 ) — Net book value at December 31, 2015 6,881 8,440 1,149 16,470 Gross book value at end of period 15,863 18,538 1,149 35,550 Accumulated depreciation and impairment at end of period (8,982 ) (10,098 ) — (19,080 ) Net book value at January 1, 2016 6,881 8,440 1,149 16,470 Additions to intangible assets 7,972 553 — 8,525 Amortization expense (3,449 ) (4,969 ) — (8,418 ) Change in consolidation scope 3 86,230 788 87,021 Currency translation adjustment (455 ) (185 ) (14 ) (654 ) Transfer into service 435 594 (1,029 ) — Net book value at December 31, 2016 $ 11,387 $ 90,663 $ 894 $ 102,944 Gross book value at end of period 22,770 106,328 894 129,992 Accumulated depreciation and impairment at end of period (11,383 ) (15,665 ) — (27,048 ) Additions to software consist mainly of internal-use software and IT licenses. Additions to technology and customer relationships relate to a preliminary valuation of Monsieur Drive and HookLogic identified intangibles, as the purchase price allocation is in progress as of December 31, 2016 (classified under “Change in consolidation scope”). Amortization on technology and customer relationships relates to Monsieur Drive, Datapop, Tedemis and Ad-X Limited) intangibles resulting from business combinations. As of December 31, 2016 , expected amortization expense for intangible assets other than intangible assets recognized in conjunction with the HookLogic acquisition (refer to Note 3) for the next five years is as follows (in thousands): Software Technology and customer relationships Total 2017 $ 5,116 $ 2,709 $ 7,825 2018 4,321 2,411 6,732 2019 2,218 436 2,654 2020 586 — 586 2021 11 — 11 Total $ 12,252 $ 5,556 $ 17,808 The average life of the software, the technology and customer relationships is 3 years.

Non-Current Financial Assets

Non-Current Financial Assets	12 Months Ended
	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Non-Current Financial Assets	Non-Current Financial Assets Non-current financial assets are mainly composed of (i) an interest-bearing bank deposit amounting to $6.6 million , which is pledged to the benefit of a bank in order to secure the first-demand bank guarantee in connection with our headquarters premises, and (ii) guarantee deposits for office rentals in France, Spain, the United Kingdom, the United States, Japan, China and Singapore.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Goodwill (in thousands) Balance at January 1, 2015 $ 27,856 Additions to goodwill 16,695 Currency translation adjustment (2,578 ) Balance at December 31, 2015 41,973 Additions to goodwill 169,197 Currency translation adjustment (1,752 ) Balance at December 31, 2016 $ 209,418 For a discussion of additions to goodwill in 2016 (acquisitions of HookLogic and Monsieur Drive), please refer to Note 2. On February 17, 2015, we acquired all of the outstanding shares of DataPop, Inc., a Los Angeles-based company specializing in the optimization of shopping campaigns on large search engines. The total consideration paid was $22.0 million ( $3.7 million as cash advances and $18.3 million for the acquisition of shares). As a result of the purchase price allocation, a technology asset of $7.8 million was identified. Residual goodwill has been valued at $16.7 million . Acquisition costs amounting to $0.6 million were fully expensed as incurred. On April 7, 2014, we acquired all the outstanding shares of AdQuantic, a bidding technology company headquartered in Paris. The total consideration paid for the acquisition was $4.1 million ( €3.0 million ) paid in cash at the acquisition date. Consequently, as of December 31, 2014, further to the purchase price allocation, goodwill was recognized for $3.9 million ( €2.8 million ) corresponding to the workforce and know-how acquired. Acquisition costs amounting to $0.1 million ( €0.1 million ) were fully expensed as incurred. On February 19, 2014, we acquired all the outstanding shares of Tedemis, a leading provider of real­time personalized email marketing solutions that help advertisers turn web visitors into customers. The total consideration paid for the acquisition was $29 million ( €21.0 million ) composed as follows: $23.4 million ( €17.0 million ) paid in cash at the acquisition date and $5.5 million ( €4.0 million ) as deferred consideration, contingent upon certain milestones over a 2 year period. As of December 31, 2014, further to the purchase price allocation the following assets have been identified: technology for $3.9 million ( €2.8 million ), cookie pool for $6.3 million ( €4.6 million ) and related deferred taxes for $3.2 million ( €2.3 million ). Residual goodwill has been valued at $21.6 million ( €15.6 million ). Acquisition costs were fully expensed as incurred for a total amount of $0.5 million ( €0.4 million ) (of which $0.1 million ( €0.1 million ) was incurred during the period ended December 31, 2013). Identified intangibles assets are amortized and an impairment test is performed on the goodwill annually.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Changes in provisions during the presented periods are summarized below: Provision for employee- related litigation Provision for tax- related litigation Other provisions Total (in thousands) Balance at January 1, 2015 $ 781 $ 592 $ — $ 1,373 Charges 200 44 388 632 Provision used (487 ) — — (487 ) Provision released not used (186 ) (541 ) — (727 ) Currency translation adjustments (72 ) (51 ) — (123 ) Balance at January 1, 2016 $ 236 $ 44 $ 388 $ 668 Charges 671 — 166 837 Provision used (402 ) — (48 ) (450 ) Provision released not used — (44 ) (347 ) (391 ) Currency translation adjustments (20 ) — 10 (10 ) Balance at December 31, 2016 $ 485 $ — $ 169 $ 654 - of which current $ 485 $ — $ 169 $ 654 The amount of the provisions represent management’s best estimate of the future outflow. Provisions are mainly in relation to employee-related litigation and other provisions which consist of estimated restoration costs following the end of leases in 2015 and 2016. The remaining provision was for tax contingencies relating to a tax inspection covering the fiscal years 2008 and 2009, which released upon receipt of the tax notification as of December 31, 2015. Commitments and contingencies Operating Lease Arrangements Future payment obligations under non-cancellable operating leases as of December 31, 2016 are listed below: Less than 1 year 1 to 5 years 5 years + Total (in thousands) Minimum payments for property leases $ 33,655 $ 98,938 $ 49,551 $ 182,144 Minimum payments for hosting services 50,959 48,927 — 99,886 Minimum payments for other leases $ 4,197 $ 4,912 $ — $ 9,109 Operating Lease Expenses Operating lease expenses relating to our offices totaled $32.1 million , $23.6 million and $18.8 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. Operating lease expenses relating to hosting services totaled $42.0 million , $30.4 million , and $24.8 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. Revolving Credit Facilities, Credit Lines Facilities and Bank Overdrafts As mentioned in Note 14, we are party to three RCFs including one with BPI France, for which we can draw up to €1.0 million ( $1.1 million ), one with HSBC for which we can draw up to RMB 40.0 million ( $5.8 million ), and one with a syndicate of banks which allow us to draw up to €250.0 million ( $263.5 million ). As of December 31, 2016, €0.1 million ( $0.1 million ), RMB 30.0 million ( $4.3 million ), and $75.0 million had been drawn, respectively. All of these credit facilities are unsecured and contain customary events of default but do not contain any affirmative, financial or negative covenants, with the exception of the €250.0 million ( $263.5 million ) RCF which contains covenants, including compliance with a total net debt to adjusted EBITDA ratio and restrictions on incurring additional indebtedness. At December 31, 2016 , we were in compliance with the required leverage ratio. We are also party to short-term credit lines and overdraft facilities with HSBC plc, and LCL. We are authorized to draw up to a maximum of €9.4 million ( $9.9 million ) in the aggregate under the short-term credit lines and overdraft facilities. As of December 31, 2016 , we had not drawn on any of these facilities. Any loans or overdraft under these short-term facilities bear interest based on the one month EURIBOR rate or three month EURIBOR rate. As these facilities are exclusively short-term credit and overdraft facilities, our banks have the ability to terminate such facilities on short notice. Contingencies From time to time we may become involved in legal proceedings or be subject to claims arising in the ordinary course of our business. We are not presently a party to any legal proceedings that, if determined adversely to us, would individually or taken together have a material adverse effect on our business, results of operations, financial condition or cash flows. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors.

Other Current Liabilities

Other Current Liabilities	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Other Current Liabilities	Other Current Liabilities Other current liabilities are presented in the following table: Year Ended December 31, 2015 2016 (in thousands) Clients' prepayments $ 6,244 $ 9,176 Employee-related payables 42,275 55,874 Taxes payable 30,463 44,831 Accounts payable relating to capital expenditures 8,037 15,484 Other creditors 1,091 2,440 Deferred revenue 159 3,121 Total $ 88,269 $ 130,926

Financial Liabilities

Financial Liabilities	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Financial Liabilities	Financial Liabilities The changes in current and non-current financial liabilities during the periods ended December 31, 2015 and December 31, 2016 are illustrated in the following schedules: As of December 31, 2014 New borrowings Repayments Liabilities assumed in connection with business combinations Other (1) Currency translation adjustment As of December 31, 2015 (in thousands) Borrowings $ 8,007 $ 4,023 $ (8,716 ) $ 1,796 $ 1,599 $ (736 ) $ 5,973 Financial liabilities relating to finance leases 282 — (258 ) — 24 (25 ) 23 Other financial liabilities 488 — (1,000 ) 1,000 174 (54 ) 608 Financial derivatives 743 — — — (116 ) (75 ) 552 Financial liabilities - current portion 9,520 4,023 (9,974 ) 2,796 1,681 (890 ) 7,156 Borrowings 5,044 — — — (1,275 ) (497 ) 3,272 Financial liabilities relating to finance leases 25 — — — (24 ) (1 ) — Other financial liabilities 191 — — — (174 ) (17 ) — Financial liabilities - non current portion 5,260 — — — (1,473 ) (515 ) 3,272 Borrowings 13,051 4,023 (8,716 ) 1,796 324 (1,233 ) 9,245 Financial liabilities relating to finance leases 307 — (258 ) — — (26 ) 23 Other financial liabilities 679 — (1,000 ) 1,000 — (71 ) 608 Financial derivatives 743 — — — (116 ) (75 ) 552 Total $ 14,780 $ 4,023 $ (9,974 ) $ 2,796 $ 208 $ (1,405 ) $ 10,428 (1) Includes reclassification from non-current to current portion based on maturity of the financial liabilities. As of December 31, 2015 New borrowings Repayments Liabilities assumed in connection with business combinations Other (1) Currency translation adjustment As of December 31, 2016 (in thousands) Borrowings $ 5,973 $ 5,846 $ (13,854 ) $ 7,067 $ 808 $ (316 ) $ 5,524 Financial liabilities relating to finance leases 23 — (27 ) — — 4 — Other financial liabilities 608 64 (286 ) 318 (225 ) (2 ) 477 Financial derivatives 552 — — — 1,505 (89 ) 1,968 Current portion 7,156 5,910 (14,167 ) 7,385 2,088 (403 ) 7,969 Borrowings 3,272 78,752 — — (808 ) (3,819 ) 77,397 Other financial liabilities — — — — 225 (11 ) 214 Non current portion 3,272 78,752 — — (583 ) (3,830 ) 77,611 Borrowings 9,245 84,598 (13,854 ) 7,067 — (4,135 ) 82,921 Financial liabilities relating to finance leases 23 — (27 ) — — 4 — Other financial liabilities 608 64 (286 ) 318 — (13 ) 691 Financial derivatives 552 — — — 1,505 (89 ) 1,968 Total $ 10,428 $ 84,662 $ (14,167 ) $ 7,385 $ 1,505 $ (4,233 ) $ 85,580 (1) Includes reclassification from non-current to current portion based on maturity of the financial liabilities. We are party to several loan agreements and revolving credit facilities, or RCF, with third-party financial institutions. Our loans and RCF agreements are presented in the table below: Nominal/ Authorized amounts Amount drawn as of December 31, 2016 (RCF only) Nature (in thousands) Interest rate Settlement date Central loan agreements BPI Loan February 20, 2014 € 3,000 N/A Fixed: 2.09% May 31, 2021 Central RCF BPI RCF February 20, 2014 € 2,000 € 50 Floating rate: EURIBOR 3M + 0.7% 0.39% as of December 31, 2016 February 28, 2017 Bank Syndicate RCF September 24, 2015 € 250,000 $ 75,000 Floating rate: EURIBOR / LIBOR + margin depending on leverage ratio 1.73% as of December 31, 2016 September 23, 2020 China RCF HSBC RCF May 12, 2015 RMB 40,000 RMB 30,000 Floating rate: + 10% 4.79% as of December 31, 2016 N/A In September 2015, Criteo entered into a five year revolving credit facility for general corporate purposes, including acquisitions, for a maximum amount of €250 million ( $263.5 million ), with a bank syndicate composed of Natixis (coordinator and documentation agent), Le Credit Lyonnais (LCL) (facility agent), HSBC France, Société Générale Corporate & Investment Banking and BNP Paribas (each acting individually as bookrunners and mandated lead arrangers). This multi-currency revolving credit facility bears interest rate at Euribor or the relevant Libor plus a variable margin (adjusted on the basis of the leverage ratio). As of December 31, 2016, $75.0 million had been drawn. We were party to a loan agreement with Le Credit Lyonnais, or LCL, to finance certain capital expenditures. The outstanding principal and interest were payable in equal monthly installments and matured in June 2016. As a result, at December 31, 2016 , the loan agreement was fully repaid. In February 2014, we entered into an agreement with Bpifrance Financement (French Public Investment Bank) to support our development. This is a fixed rate seven -year term loan for €3 million ( $3.2 million ) which will be amortized quarterly after a two -year grace period. In February 2014, we also entered into a three -year RCF with Bpifrance Financement (French Public Investment Bank). Upon origination, this agreement allowed for a maximum amount of €3.0 million ( $3.2 million ) in the first year, decreasing by €1.0 million ( $1.0 million ) in each subsequent year. As of December 31, 2016, we are authorized to draw €1.0 million ( $1.0 million ). The interest rate is Euribor 3 months plus a 0.70% margin. A 0.30% commitment fee is due on a quarterly basis depending on the amount used. At December 31, 2016 , €0.1 million ( $0.1 million ) had been drawn. In October 2014, and as amended in May 2015, we entered into a revolving loan facility with HSBC to support the development of our Chinese subsidiary for a total amount RMB 40.0 million ( $5.8 million ). Interest is determined at a rate equal to the benchmark lending rate effective on the loan drawdown date promulgated by the People’s Bank of China with a 10% mark up and payable when the loan matures. At December 31, 2016 , RMB 30 million ( $4.3 million ) had been drawn. All of these loans and revolving credit facilities are unsecured and contain customary events of default but do not contain any affirmative, financial or negative covenants, with the exception of the September 2015 revolving credit facility which contains covenants, including compliance with a total net debt to adjusted EBITDA ratio and restrictions on the incurrence of additional indebtedness. At December 31, 2016 , we were in compliance with the required leverage ratio. The following table shows the maturity of our financial liabilities: Maturity Carrying value 2017 2018 2019 2020 2021 2022 (in thousands) Borrowings $ 82,921 $ 5,522 $ 817 $ 632 $ 75,634 $ 316 $ — Financial liabilities relating to finance leases — — — — — — — Other financial liabilities 691 477 — 214 — — — Bank overdraft — — — — — — — Financial derivatives 1,968 1,968 — — — — — Financial liabilities 85,580 7,967 817 846 75,634 316 —

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2016
Postemployment Benefits [Abstract]
Employee Benefits	Employee Benefits Defined Benefit Plans According to the French law and the Syntec Collective Agreement, French employees are entitled to compensation paid on retirement. The following table summarizes the changes in the projected benefit obligation: Year Ended December 31, 2014 2015 2016 (in thousands) Projected benefit obligation present value—beginning of period $ 1,276 $ 1,245 $ 1,445 Service cost 492 441 524 Interest cost 33 22 37 Actuarial losses (gains) (512 ) (128 ) 1,335 Change in consolidation scope 119 — 19 Currency translation adjustment (163 ) (135 ) (139 ) Projected benefit obligation present value—end of period $ 1,245 $ 1,445 $ 3,221 The Company does not hold any plan assets for any of the periods presented. The reconciliation of the changes in the present value of projected benefit obligation with the Consolidated Statements of Income for the presented periods is illustrated in the following table: Year Ended December 31, 2014 2015 2016 (in thousands) Service cost $ (492 ) $ (441 ) $ (524 ) Research and development expenses (167 ) (163 ) (211 ) Sales and operations expenses (188 ) (153 ) (144 ) General and administrative expenses (137 ) (125 ) (169 ) Interest cost (33 ) (22 ) (37 ) Financial income (expense) (33 ) (22 ) (37 ) Actuarial gains (losses) 512 128 (1,335 ) Accumulated other comprehensive income 512 128 (1,335 ) Amortization of net loss (gain) 12 — — The main assumptions used for the purposes of the actuarial valuations are listed below: Year Ended December 31, 2014 2015 2016 Discount rate (Corp AA) 1.5% 2.5% 1.9% Expected rate of salary increase 5.0% 5.0% 5.0% Expected rate of social charges 44.0% - 47.6% 48.0% - 51.0% 49.0% - 51.0% Expected staff turnover 0 - 15% 0 - 15% 0 - 10.5% Estimated retirement age 65 years old 65 years old Progressive table Life table INSEE - 2007 - 2009 TGHF 2005 TH-TF 2000-2002 shifted Defined Contribution Plans The total expense represents contributions payable to these plans by us at specified rates. The Group makes earnings-related payments, in accordance with local customs, to the national organizations responsible for paying pensions and similar financial benefits. The main contributions concern France, the United States, for 401k plans, and the United Kingdom. Year Ended December 31, 2014 2015 2016 (in thousands) Defined contributions plans included in personnel expenses $ (6,522 ) $ (8,320 ) $ (11,061 )

Common Shares

Common Shares	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Common Shares	Common shares We manage our capital to ensure that entities in the Company will be able to continue as a going concern while maximizing the return to stakeholders through the optimization of the debt and equity balance. Our capital structure consists of financial liabilities (as detailed in Note 14 offset by cash and bank balances) and equity (comprising issued capital, reserves, retained earnings and non-controlling interests). We are not subject to any externally imposed capital requirements. Issued Capital As of December 31, 2016 , the Parent’s share capital was composed of 63,978,204 ordinary shares, each with a nominal value of €0.025 , i.e. a total amount of €1.6 million , or $2.1 million . Change in Number of Shares Number of ordinary shares Balance at January 1, 2015 60,902,695 Issuance of shares under share option and free share plans (1) 1,568,186 Balance at December 31, 2015 62,470,881 Issuance of shares under share option and free share plans (2) 1,507,323 Balance at December 31, 2016 63,978,204 (1) Adopted by the Board of Directors on January 29, 2015, March 19, 2015, April 30, 2015, July 30, 2015, October 29, 2015 and December 17, 2015. (2) Adopted by the Board of Directors on January 29, 2016, February 25, 2016, April 20, 2016, June 28, 2016, July 28, 2016, October 27, 2016 and November 9, 2016.

Nature of Expenses Allocated by

Nature of Expenses Allocated by Function	12 Months Ended
	Dec. 31, 2016
Other Income and Expenses [Abstract]
Nature of Expenses Allocated by Function Disclosure	Nature of Expenses Allocated by Function Nature of Expenses Allocated to Cost of Revenue Year Ended December 31, 2014 2015 2016 (in thousands) Traffic acquisition costs $ (585,492 ) $ (789,152 ) $ (1,068,911 ) Other cost of revenue (47,948 ) (62,201 ) (85,260 ) Hosting costs (24,780 ) (30,428 ) (41,978 ) Depreciation and amortization (21,455 ) (29,866 ) (38,469 ) Data acquisition (600 ) (257 ) (122 ) Other cost of sales (1,113 ) (1,650 ) (4,691 ) Total cost of revenue $ (633,440 ) $ (851,353 ) $ (1,154,171 ) Nature of Expenses Allocated to Research and Development Year Ended December 31, 2014 2015 2016 (in thousands) Personnel expenses $ (40,075 ) $ (58,075 ) $ (86,389 ) Personnel expense excluding equity awards compensation expense and research tax credit (41,456 ) (54,941 ) (79,222 ) Equity awards compensation expense (3,682 ) (6,520 ) (12,108 ) Research tax credit 5,063 3,386 4,941 Other cash operating expenses (14,888 ) (21,081 ) (29,867 ) Subcontracting and other headcount related costs (8,218 ) (12,592 ) (14,713 ) Rent and facilities costs (5,765 ) (7,107 ) (10,939 ) Consulting and professional fees (765 ) (1,201 ) (2,423 ) Marketing costs (97 ) (161 ) (953 ) Other (43 ) (20 ) (839 ) Other non-cash operating expenses (5,112 ) (7,651 ) (7,393 ) Depreciation and amortization (4,949 ) (7,995 ) (7,211 ) Net change in other provisions (163 ) 344 (182 ) Total research and development expenses $ (60,075 ) $ (86,807 ) $ (123,649 ) Nature of Expenses Allocated to Sales and Operations Year Ended December 31, 2014 2015 2016 (in thousands) Personnel expenses $ (119,609 ) $ (150,426 ) $ (185,065 ) Personnel expense excluding equity awards compensation expense (107,319 ) (138,748 ) (168,227 ) Equity awards compensation expense (12,290 ) (11,678 ) (16,838 ) Other cash operating expenses (52,077 ) (71,034 ) (84,127 ) Subcontracting and other headcount related costs (17,363 ) (20,856 ) (22,460 ) Rent and facilities costs (15,684 ) (25,542 ) (29,968 ) Marketing costs (9,443 ) (12,478 ) (15,225 ) Other (9,587 ) (12,158 ) (16,474 ) Other non-cash operating expenses (5,241 ) (8,070 ) (13,661 ) Depreciation and amortization (3,664 ) (5,178 ) (7,757 ) Net change in provisions for doubtful receivables (1,342 ) (2,660 ) (5,433 ) Net change in other provisions (235 ) (232 ) (471 ) Total sales and operations expenses $ (176,927 ) $ (229,530 ) $ (282,853 ) Nature of Expenses Allocated to General and Administrative Year Ended December 31, 2014 2015 2016 (in thousands) Personnel expenses $ (29,734 ) $ (37,670 ) $ (60,899 ) Personnel expense excluding equity awards compensation expense (26,106 ) (31,879 ) (46,586 ) Equity awards compensation expense (3,628 ) (5,791 ) (14,313 ) Other cash operating expenses (33,430 ) (41,814 ) (52,867 ) Subcontracting and other headcount related costs (17,452 ) (19,963 ) (22,990 ) Rent and facilities costs (4,731 ) (6,475 ) (9,516 ) Consulting and professional fees (10,094 ) (12,921 ) (18,298 ) Other (1,153 ) (2,455 ) (2,063 ) Other non-cash operating expenses (1,559 ) 339 (3,703 ) Depreciation and amortization (1,145 ) (1,526 ) (3,342 ) Net change in other provisions (414 ) (353 ) (361 ) Other — 2,218 — Total general and administrative expenses $ (64,723 ) $ (79,145 ) $ (117,469 )

Allocation of Personnel Expense

Allocation of Personnel Expenses	12 Months Ended
	Dec. 31, 2016
Compensation Related Costs [Abstract]
Allocation of Personnel Expenses	Allocation of Personnel Expenses Allocation of Personnel Expenses By Function Year Ended December 31, 2014 2015 2016 (in thousands) Research and development expenses $ (40,075 ) $ (58,075 ) $ (86,389 ) Sales and operations expenses (119,609 ) (150,426 ) (185,065 ) General and administrative expenses (29,734 ) (37,670 ) (60,899 ) Total personnel expenses $ (189,418 ) $ (246,171 ) $ (332,353 ) Allocation of Personnel Expenses by Nature Year Ended December 31, 2014 2015 2016 (in thousands) Wages and salaries $ (128,737 ) $ (170,079 ) $ (220,317 ) Severance pay (2,469 ) (1,343 ) (2,726 ) Social charges (38,814 ) (47,176 ) (59,668 ) Other social expenses (3,178 ) (6,033 ) (9,913 ) Acquisition-related deferred price consideration (950 ) (324 ) (85 ) Share based compensation (19,600 ) (23,989 ) (43,259 ) Profit sharing (733 ) (613 ) (1,326 ) Research tax credit (classified as a reduction of R&D expenses) 5,063 3,386 4,941 Total personnel expenses $ (189,418 ) $ (246,171 ) $ (332,353 )

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation Share Options Plans and Employee Warrants Grants (BSPCE) The Board of Directors has been authorized by the general meeting of the shareholders to grant employee warrants (Bons de Souscription de Parts de Créateur d’Entreprise or “BSPCE”) and to implement share options plans as follows: • Issuance of 2,112,000 BSPCE, authorized at the General Meeting of Shareholders on October 24, 2008, making available up to 2,112,000 BSPCE until April 24, 2010 (“Plan 1”); • Issuance of 1,472,800 BSPCE, authorized at the General Meeting of Shareholders on April 16, 2009, making available up to 1,472,800 BSPCE until October 16, 2010 (“Plan 2”); • 1,584,000 Share Options, authorized at the General Meeting of Shareholders on September 9, 2009, making available up to 1,584,000 share options until November 8, 2012. This Plan has been amended at the General Meeting of Shareholders on November 16, 2010, making available up to 2,700,000 share options or BSPCE (“Plan 3”); • Issuance of 361,118 BSPCE, granted to Criteo co-founders at the General Meeting of Shareholders on April 23, 2010 (“Plan 4”); • 2,800,000 BSPCE or Share Options (Options de Souscription d'Actions or “OSA”) , authorized at the General Meeting of Shareholders on November 18, 2011, making available up to 2,800,000 share options or BSPCE (“Plan 5”); • 1,654,290 BSPCE or Share Options, authorized at the General Meeting of Shareholders on September 14, 2012, making available up to 1,654,290 share options or BSPCE (“Plan 6”). • 6,627,237 BSPCE or Share Options, authorized at the General Meeting of Shareholders on August 2, 2013, making available up to 6,627,237 share options or BSPCE (“Plan 7”). • 9,935,710 Share Options, authorized at the General Meeting of Shareholders on June 18, 2014, making available up to 9,935,710 share options (“Plan 8”). The Board of Directors has also authorized free shares/restricted stock units ("RSUs") to Criteo employees under presence condition and to certain senior managers, employees and members of the Management, subject to the achievement of internal performance objectives and presence condition. • 4,600,000 Share Options or RSUs, authorized at the General Meeting of Shareholders on June 29, 2016 and 100,000 BSAs (any BSA granted will also be deducted from the 4,600,000 limit), such authorizations collectively referred to as “Plan 9”. The Board of Directors has authorized RSUs to Criteo employees subject to a presence condition and to certain senior managers, employees and members of management, subject to the achievement of internal performance objectives and a presence condition. Upon exercise of the BSPCE or OSA, or the vesting of an RSU we offer beneficiaries newly issued ordinary shares of the Parent. The BSPCEs and OSAs may be exercised by the beneficiary on the basis of the following vesting schedule for the Plans 1, 2 and 3: • up to one third (1/3) of the BSPCE on the first anniversary of the date of grant; • up to one twelfth (1/12) at the expiration of each quarter following the first anniversary of the date of grant, and this during twenty-four ( 24 ) months thereafter; and • at the latest within ten ( 10 ) years from the date of grant. For the Plan 3 amended to Plan 9, the vesting schedule is as follows: • up to one fourth (1/4) of the BSPCE/share options on the first anniversary of the date of grant; • up to one-sixteenth (1/16) at the expiration of each quarter following the first anniversary of the date of grant, and this during thirty-six ( 36 ) months thereafter; and • at the latest within ten ( 10 ) years from the date of grant. The vesting schedule for the RSUs is as follows: • 50% at the expiration of a two year period • 6.25% at the expiration of each quarter following the first two years-period during twenty four ( 24 ) months. When the Company was not listed, exercise prices were determined by reference to the latest capital increase as of the date of grant, unless the Board of Directors decided otherwise. Since our initial public offering, exercise prices are determined by reference to the closing share price the day before the date of the grant if higher than a floor value of 95% of the average of the closing share price for the last 20 trading days. In the following tables, exercise prices, grant date share fair values and fair value per equity instruments are provided in euros, as the Company is incorporated in France and the euro is the currency used for the grants. Details of BSPCE / OSA / RSU plans Plans 1 & 2 Plan 3 Plan 4 Plan 5 Plan 6 Plan 6 Plan 7 Plan 8 Plan 9 Dates of grant (Boards of Directors) Oct 24, 2008 - Sept 14, 2010 Sept 9, 2009 - Sept 21, 2011 April 23, 2010 Nov 18, 2011 - May 22, 2012 Oct 25, 2012 Oct 25, 2012 - Sept 3, 2013 - April 23, 2014 July 30, 2014 - June 28, 2016 July 28, 2016 - Nov 9, 2016 Vesting period 3 years 3 - 4 years None 4 years 1 year 4-5 years 4 years 4 years 4 years 4 years 4 years Contractual life 10 years 10 years 10 years 10 years 10 years 10 years 10 years 10 years — 10 years — Expected option life 8 years 8 years 8 years 8 years 8 years 8 years 6 - 8 years 6 years — 6 years — Number of instruments granted 1,819,120 4,289,940 361,118 1,184,747 257,688 1,065,520 2,317,374 4,318,551 2,534,262 147,400 1,153,383 Type : Share Option (S.O.) / BSPCE / RSU BSPCE BSCPCE & OSA BSPCE BSCPCE & OSA BSPCE BSCPCE & OSA BSCPCE & OSA OSA RSU OSA RSU Share entitlement per option 1 1 1 1 1 1 1 1 1 1 1 Exercise price € 0.45 - € 0.20 - € 2.10 € 5.95 € 8.28 € 8.28 - € 12.08 - € 22.95 - — € 38.20 — Valuation method Black & Scholes Grant date share fair value € 0.20 - € 0.20 - € 2.10 € 4.98 € 6.43 € 5.45 - € 12.08 - € 22.50 - € 35.18 - € 38.20 € 33.98 - Expected volatility (1) 53.0% - 55.7% 55.2% - 57.8% 55.2% 52.1% - 52.9% 50.2% 49.6% - 50.2% 44.2% - 50.1% 39.4% - 44.5% — — — Discount rate (2) 2.74% - 4.10% 2.62% - 3.76% 3.4% 2.79% - 3.53% 2.2% 1.80% - 2.27% 1.20% - 2.40% 0.00% - 0.71% — — — Performance conditions No Yes (A) No No Yes (B) No No No Yes (C) No Yes (D) Fair value per option / RSU € 0.08 - € 0.08 - € 1.33 € 2.75 - € 3.28 € 3.28 - € 6.85 - € 9.47 - € 26.16 - € 14.49 € 33.98 - (1) Based on similar listed entities. (2) Based on Obligation Assimilables du Trésor, i.e. French government bonds with a ten -year maturity (“TEC 10 OAT floating-rate bonds”). (A) Options subject to performance condition: Among the 960,000 share options granted in April 7, 2011, 180,000 are subjected to performance conditions based on revenue excluding traffic acquisition costs targets that were met in 2012. (B) On October 25, 2012, the Board of Directors of the Parent also granted a total of 257,688 BSPCE to our co-founders. The conditions of exercise of these BSPCE are linked to a future liquidity event or a transfer of control of the Company, and the number of BSPCE that can be exercised are determined by the event’s date which cannot occur after March 31, 2014. Based on the assumptions known as at December 31, 2012, we determined that the share-based compensation expense would be recognized over a one -year period. This assumption was confirmed in 2013. (C) On October 29, 2015, the Board of Directors of the Parent also granted a total of 337,960 RSU to Criteo employees under condition of presence and to certain senior managers, employees and members of the management, subject to the achievement of internal performance objectives and condition of presence. Based on the assumptions known at December 31, 2015, we determined the share-based compensation expense by applying a probability ratio on performance objectives completion. This assumption was confirmed in 2016. On January 29, 2016, the Board of Directors of the Parent granted a total of 33,010 RSUs to members of the management, subject to the achievement of internal performance objectives and condition of presence. Based on the assumptions known at December 31, 2016, we determined the share-based compensation expense by applying a probability ratio on performance objectives completion. (D) On July 28, 2016, the Board of Directors of the Parent granted a total of 195,250 RSUs to certain senior managers and members of the management, subject to the achievement of internal performance objectives and condition of presence. Based on the assumptions known at December 31, 2016, we determined the share-based compensation expense by applying a probability ratio on performance objectives completion. Change in Number of BSPCE / OSA / RSU Plans 1 & 2 Plan 3 Plan 4 Plan 5 Plan 6 Plan 7 Plan 8 Plan 9 RSUs Total Balance at January 1, 2014 1,134,737 2,333,763 361,118 1,929,299 1,204,248 1,555,144 — — — 8,518,309 Granted — — — — — 749,330 2,267,774 — — 3,017,104 Exercised (930,660 ) (1,315,733 ) (273,559 ) (337,352 ) (271,520 ) (47,019 ) — — — (3,175,843 ) Forfeited — (82,439 ) — (407,222 ) (42,928 ) (440,320 ) (30,820 ) — — (1,003,729 ) Balance at December 31, 2014 204,077 935,591 87,559 1,184,725 889,800 1,817,135 2,236,954 — — 7,355,841 Granted — — — — — — 1,621,734 — 1,103,405 2,725,139 Exercised (116,520 ) (449,069 ) (87,559 ) (343,021 ) (156,801 ) (310,827 ) (69,819 ) — — (1,533,616 ) Forfeited — (148,864 ) — (22,357 ) (40,068 ) (218,730 ) (466,086 ) — (7,820 ) (903,925 ) Balance at December 31, 2015 87,557 337,658 — 819,347 692,931 1,287,578 3,322,783 — 1,095,585 7,643,439 Granted — — — — — — 429,043 147,400 2,584,240 3,160,683 Exercised (33,403 ) (162,265 ) — (310,236 ) (281,166 ) (383,127 ) (300,126 ) — — (1,470,323 ) Forfeited — 300 — 3,956 (12,324 ) (153,923 ) (508,866 ) (23,025 ) (436,546 ) (1,130,428 ) Balance at December 31, 2016 54,154 175,693 — 513,067 399,441 750,528 2,942,834 124,375 3,243,279 8,203,371 Breakdown of the Closing Balance Plans 1 & 2 Plan 3 Plan 4 Plan 5 Plan 6 Plan 7 Plan 8 Plan 9 RSUs Total Balance at December 31, 2014 Number outstanding 204,077 935,591 87,559 1,184,725 889,800 1,817,135 2,236,954 — — 7,355,841 Weighted-average exercise price € 1.08 € 2.08 € 2.10 € 5.95 € 9.81 € 18.29 € 23.40 € — € — € 14.10 Number exercisable 204,077 883,399 87,559 730,371 362,778 394,785 — — — 2,662,969 Weighted-average exercise price € 1.08 € 1.94 € 2.10 € 5.95 € 9.58 € 14.02 € — € — € — € 5.81 Weighted-average remaining contractual life 4.6 years 5.8 years 5.3 years 7.3 years 8.1 years 8.9 years 9.6 years — — 8.2 years Balance at December 31, 2015 Number outstanding 87,557 337,658 — 819,347 692,931 1,287,578 3,322,783 — 1,095,585 7,643,439 Weighted-average exercise price € 1.41 € 3.14 € — € 5.95 € 9.75 € 17.97 € 30.50 € — € — € 20.97 Number exercisable 87,557 337,658 — 713,165 420,228 564,034 521,578 — — 2,644,220 Weighted-average exercise price € 1.41 € 3.14 € — € 5.95 € 9.58 € 17.24 € 23.32 € — € — € 11.85 Weighted-average remaining contractual life 3.6 years 4.8 years — 6.3 years 7.1 years 7.9 years 8.9 years — — 7.9 years Balance at December 31, 2016 Number outstanding 54,154 175,693 — 513,067 399,441 750,528 2,942,834 124,375 3,243,279 8,203,371 Weighted-average exercise price € 1.24 € 3.29 € — € 5.95 € 9.77 € 18.13 € 31.32 € 38.20 € — € 23.92 Number exercisable 54,154 175,693 — 513,067 325,596 504,262 1,135,634 — — 2,708,406 Weighted-average exercise price € 1.24 € 3.29 € — € 5.95 € 9.66 € 17.94 € 28.96 € — € — € 17.73 Weighted-average remaining contractual life 2.9 years 4.3 years — 5.2 years 6.1 years 6.8 years 8.2 years 9.6 years — 6.9 years Non-Employee Warrants (Bons de Souscription d’Actions or BSA) In addition to the RSUs, share options and BSPCE grants, the shareholders of the Parent also authorized the grant of non-employee warrants or Bons de Souscription d’Actions (“BSA”), as indicated below: • Plan A : up to one-eight (1/8) at the expiration of each quarter following the date of grant, and this during twenty-four ( 24 ) months; and at the latest within ten ( 10 ) years as from the date of grant. • Plan B : up to one third (1/3) of the non-employee warrants on the first anniversary of the date of grant; then up to one twelfth (1/12) at the expiration of each quarter following the first anniversary of the beginning of the vesting period, and this during twenty-four ( 24 ) months thereafter; and at the latest within ten ( 10 ) years as from the date of grant. • Plan C : up to one-twenty fourth (1/24) at the expiration of each month following the date of grant, and this during twenty-four ( 24 ) months, and at the latest within ten ( 10 ) years as from the date of grant. • Plan D (member of the advisory board) : up to one-twenty fourth (1/24) at the expiration of each month following the date of grant, and this during twenty-four ( 24 ) months; and at the latest within ten ( 10 ) years as from the date of grant. • Plan D (not member of the advisory board) : one-third (1/3) at the date of grant; one third (1/3) at the first anniversary of the date of grant; one third (1/3) at the second anniversary of the date of grant; and at the latest within ten ( 10 ) years as from the date of grant. • Plans E and F : up to one fourth (1/4) of the non-employee warrants on the first anniversary of the date of grant; up to one-sixteenth (1/16) at the expiration of each quarter following the first anniversary of the date of grant, and this during thirty-six ( 36 ) months thereafter; and at the latest within ten ( 10 ) years from the date of grant. Upon exercise of the non-employee warrants, we offer settlement of the warrants in newly issued ordinary shares of the Parent. Details of Non-Employee Warrants Plan A Plan B Plan C Plan D Plan E Plan F Dates of grant Nov 17, 2009 March 11, 2010 Nov 16, 2010 - Sept 21, 2011 Oct 25, 2012 - March 6, 2013 March 19, 2015 - Oct 29, 2015 April 20, 2016 - Oct 27, 2016 Vesting period 2 years 3 years 2 years 2 years 1 - 4 years 1 - 4 years Contractual life 10 years 10 years 10 years 10 years 10 years 10 years Number of warrants granted 231,792 277,200 192,000 125,784 38,070 48,655 Share entitlement per warrant 1 1 1 1 1 1 Share warrant price €0.02 €0.07 - €0.11 €0.04 - €0.30 €0.43 - €0.48 €9.98 - €16.82 €13.89 - €14.55 Exercise price €0.70 €0.70 €0.70 - €5.95 €8.28 - €9.65 €35.18 - €41.02 €33.98 - €35.41 Valuation method used Black & Scholes Grant date share fair value €0.20 €0.70 €0.70 - €4.98 €6.43 - €9.65 €35.18 - €41.02 €33.98 - €35.41 Expected volatility (1) 55.7 % 55.2 % 53.5% - 55.0% 50.0% - 50.2% 39.9 % 40.6 % Discount rate (2) 3.58 % 3.44 % 2.62% - 3.38% 2.13% - 2.27% 0.% - 0.52% 0.10% - 0.25% Performance conditions No Yes (A) No No No No Fair value per warrant €0.05 €0.33 - €0.38 €0.40 - €2.58 €2.85 - €4.98 €9.98 - €16.82 €13.89 - €14.55 (1) Based on similar listed entities. (2) Based on Obligations Assimilables du Trésor, i.e. French government bonds with a ten-year maturity (“TEC 10 OAT floating-rate bonds”). (A) All the performance conditions were achieved during the period ended December 31, 2010. Changes in Number of Non-Employee Warrants Balance at January 1, 2014 542,148 Granted 5,040 Exercised (345,780 ) Forfeited (2,000 ) Balance at December 31, 2014 199,408 Granted 38,070 Exercised (34,568 ) Forfeited (48,000 ) Balance at December 31, 2015 154,910 Granted 48,655 Exercised (37,000 ) Forfeited 21,560 Balance at December 31, 2016 188,125 Breakdown of the Closing Balance Non-employee warrants Balance at December 31, 2014 Number outstanding 199,408 Weighted-average exercise price € 7.54 Number exercisable 155,609 Weighted-average exercise price € 6.88 Weighted-average remaining contractual life 7.5 years Balance at December 31, 2015 Number outstanding 154,910 Weighted-average exercise price € 15.72 Number exercisable 117,783 Weighted-average exercise price € 8.49 Weighted-average remaining contractual life 7.4 years Balance at December 31, 2016 Number outstanding 188,125 Weighted-average exercise price € 19.04 Number exercisable 117,096 Weighted-average exercise price € 11.73 Weighted-average remaining contractual life 7.3 years Reconciliation with the Consolidated Statements of Income Balance for the year ended December 31, 2014 Balance for the year ended December 31, 2015 Balance for the year ended December 31, 2016 (in thousands) R&D S&O G&A Total R&D S&O G&A Total R&D S&O G&A Total RSUs — — — — (706 ) (1,046 ) (544 ) (2,296 ) (9,178 ) (12,705 ) (7,287 ) (29,170 ) Share options / BSPCE (3,682 ) (12,290 ) (3,497 ) (19,469 ) (5,814 ) (10,632 ) (5,001 ) (21,447 ) (2,930 ) (4,133 ) (5,356 ) (12,419 ) Plan 3 34 15 (36 ) 13 1 (6 ) — (5 ) — — — — Plan 5 (215 ) (134 ) (257 ) (606 ) (71 ) 27 (108 ) (152 ) (8 ) (27 ) (7 ) (42 ) Plan 6 (505 ) (1,358 ) (44 ) (1,907 ) (188 ) (384 ) (13 ) (585 ) (35 ) (20 ) (162 ) (217 ) Plan 7 (1,598 ) (8,494 ) (1,134 ) (11,226 ) (884 ) (1,758 ) (379 ) (3,021 ) (234 ) 239 (194 ) (189 ) Plan 8 (1,398 ) (2,319 ) (2,026 ) (5,743 ) (4,672 ) (8,511 ) (4,501 ) (17,684 ) (2,587 ) (4,258 ) (4,638 ) (11,483 ) Plan 9 — — — — — — — — (66 ) (67 ) (355 ) (488 ) Total share-based compensation (3,682 ) (12,290 ) (3,497 ) (19,469 ) (6,520 ) (11,678 ) (5,545 ) (23,743 ) (12,108 ) (16,838 ) (12,643 ) (41,589 ) BSAs — — (131 ) (131 ) — — (246 ) (246 ) — — (1,670 ) (1,670 ) Total equity awards compensation expense $ (3,682 ) $ (12,290 ) $ (3,628 ) $ (19,600 ) $ (6,520 ) $ (11,678 ) $ (5,791 ) $ (23,989 ) $ (12,108 ) $ (16,838 ) $ (14,313 ) $ (43,259 )

Financial Income and Expenses

Financial Income and Expenses	12 Months Ended
	Dec. 31, 2016
Other Income and Expenses [Abstract]
Financial Income and Expenses	Financial Income and Expenses The Consolidated Statements of Income line item “Financial income (expense)” can be broken down as follows: Year Ended December 31, 2014 2015 2016 (in thousands) Financial income from cash equivalents $ 1,910 $ 2,105 $ 1,352 Interest and fees (583 ) (653 ) (2,367 ) Interest on debt (583 ) (553 ) (1,134 ) Fees — (100 ) (1,233 ) Foreign exchange (loss) gain 10,096 (5,971 ) 506 Other financial expense (33 ) (22 ) (37 ) Total financial income (expense) $ 11,390 $ (4,541 ) $ (546 ) The $0.5 million financial expense for the period ended December 31, 2016 resulted from the interest incurred as a result of drawing on the revolving credit facility entered into in September 2015 to partially fund the acquisition of HookLogic in November 2016, the negative impact of foreign exchange reevaluations and related hedging mainly recorded during the first quarter, partially offset by the foreign exchange gain realized on the hedging of HookLogic Inc acquisition. At the end of December 2016, the main positions bearing a risk of foreign currency are centralized at the Parent company level and hedged using foreign currency swaps or forward purchases or sales of foreign currencies. The $6.0 million foreign exchange loss for the period ended December 31, 2015 mainly results from the revaluation of the intra-group positions between Criteo S.A. and its Brazilian subsidiary, associated with a higher related cost of hedging, partially offset by a $2.1 million gain realized on the sale of the $70 million remaining from our initial public offering proceeds. At the end of December 2015, the main positions bearing a risk of foreign currency are centralized at the Parent company level and hedged using foreign currency swaps or forward purchases or sales of foreign currencies.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Breakdown of Income Taxes The Consolidated Statements of Income line item “Provision for income taxes” can be broken down as follows: Year Ended December 31, 2014 2015 2016 (in thousands) Current income tax $ (22,893 ) $ (25,265 ) $ (43,153 ) France (11,087 ) (15,458 ) (20,204 ) International (11,806 ) (9,807 ) (22,949 ) Net change in deferred taxes 5,315 15,748 10,024 France 671 2,009 2,654 International 4,644 13,739 7,370 Provision for income tax $ (17,578 ) $ (9,517 ) $ (33,129 ) As mentioned in Note 1 (Principles and Accounting Methods), the French Research Tax Credit is not included in the line item “Provision for income taxes” but is deducted from “Research and development expenses” (see Note 18 - Allocation of Personnel Expenses). French business tax, CVAE, is included in the current tax balance for an amount of $2.5 million , $3.0 million and $4.1 million , for the years ended December 31, 2014 , 2015 and 2016 respectively. Reconciliation between the Effective and Nominal Tax Expense The following table shows the reconciliation between the effective and nominal tax expense at the nominal standard French rate of 34.43% (excluding additional contributions): Year Ended December 31, 2014 2015 2016 (in thousands) Income before taxes $ 64,474 $ 71,793 $ 120,458 Theoretical group tax-rates 34.43 % 34.43 % 34.43 % Nominal tax expense (22,198 ) (24,718 ) (41,474 ) Increase / decrease in tax expense arising from: Research tax credit 1,743 1,352 1,701 Net effect of shared based compensation (1) 3,419 2,048 (8,957 ) Other permanent differences (2,245 ) (804 ) (3,518 ) Non recognition of deferred tax assets related to tax losses and temporary differences (2) (3,546 ) (7,662 ) (7,738 ) Utilization or recognition of previously unrecognized tax losses (3) 276 12,264 13,366 French CVAE included in income taxes (2,467 ) (3,052 ) (3,165 ) Special tax deductions (4) 8,984 12,545 20,022 Effect of different tax rates (1,019 ) (1,046 ) (1,108 ) Other differences (525 ) (444 ) (2,258 ) Effective tax expense $ (17,578 ) $ (9,517 ) $ (33,129 ) Effective tax rate 27.3 % 13.3 % 27.5 % Increases and decreases in tax expense are presented applying the theoretical Group tax rate to the concerned tax bases. The impact resulting from the differences between local tax rates and the Group theoretical rate is shown in the “effect of different tax rates.” (1) While in most countries share-based compensation does not give rise to any tax effect either when granted or when exercised, the United States and the United Kingdom generally permit tax deductions in respect of share-based compensation. The tax deduction generated in the United States and United Kingdom is in connection with the significant number of options exercised during the period was offset by the share-based compensation accounting expense exclusion. (2) Deferred tax assets on which a valuation allowance has been recognized mainly relate to Criteo Ltd, Criteo do Brasil, Criteo Singapore Pte. Ltd and Criteo Advertising (Beijing) Co. Ltd tax losses. (3) The 2014 balance relates exclusively to Criteo Pty. The 2015 and 2016 balances mainly relate to the recognition of Criteo Corp. tax losses considering the projected taxable income within the next 3 years and the Section IRC 382 annual limitation. (4) Special tax deductions refer to the application of a reduced income tax rate on the majority of the technology royalties income invoiced by the Parent to its subsidiaries. Deferred Tax Assets and Liabilities The following table shows the changes in the major sources of deferred tax assets and liabilities: (in thousands) Year ended December 31, 2014 Change recognized in profit or loss Change recognized in OCI Change in consolidation scope Other Currency translation adjustments Year ended December 31, 2015 Deferred tax assets: Net operating loss carryforwards $ 23,468 $ (385 ) $ — $ 5,889 $ — $ (549 ) $ 28,423 Personnel-related accruals 2,538 5,414 — 9 — (659 ) 7,302 Other accruals 2,285 1,353 — — — (545 ) 3,093 Projected benefit obligation 472 202 (44 ) — — (52 ) 578 Other 1,458 4,372 — 1,091 — (79 ) 6,842 Deferred tax assets (gross) 30,221 10,956 (44 ) 6,989 — (1,884 ) 46,238 Valuation allowance (19,863 ) 1,429 21 (7,177 ) — 1,610 (23,980 ) Deferred tax asset (net) 10,358 12,385 (23 ) (188 ) — (274 ) 22,258 Deferred tax liabilities: Intangible assets (2,861 ) 5,445 — (2,979 ) — 245 (150 ) Other (4 ) (2,082 ) — 47 — (12 ) (2,051 ) Deferred tax liabilities (2,865 ) 3,363 — (2,932 ) — 233 (2,201 ) Net deferred income tax balance $ 7,493 $ 15,748 $ (23 ) $ (3,120 ) $ — $ (41 ) $ 20,057 (in thousands) Year ended December 31, 2015 Change recognized in profit or loss Change recognized in OCI Change in consolidation scope Other Currency translation adjustments Year ended December 31, 2016 Deferred tax assets: Net operating loss carryforwards $ 28,423 $ (1,048 ) $ — $ — $ — $ (912 ) $ 26,463 Personnel-related accruals 7,302 257 — (30 ) 241 7,770 Other accruals 3,093 975 — 30 276 4,374 Projected benefit obligation 578 213 466 — — (50 ) 1,207 Other 6,842 7,331 — — (482 ) (265 ) 13,426 Deferred tax assets (gross) 46,238 7,728 466 — (482 ) (710 ) 53,240 Valuation allowance (23,980 ) 3,630 (16 ) — — 545 (19,821 ) Deferred tax asset (net) 22,258 11,358 450 — (482 ) (165 ) 33,419 Deferred tax liabilities: Intangible assets (150 ) (6 ) (477 ) — (33 ) 35 (631 ) Other (2,051 ) (1,328 ) — — 515 20 (2,844 ) Total deferred tax liabilities (2,201 ) (1,334 ) (477 ) — 482 55 (3,475 ) Net deferred income tax balance $ 20,057 $ 10,024 $ (27 ) $ — $ — $ (110 ) $ 29,944 Amounts recognized in our Consolidated Financial Statements are calculated at the level of each subsidiary within our Consolidated Financial Statements. As at December 31, 2014 , 2015 and 2016 , the valuation allowance against net deferred income taxes amounted to $26.1 million , $24.0 million and $19.9 million , which related mainly to Criteo Corp. ( $13.9 million , $12.4 million and $0.9 million , respectively), Criteo do Brasil ( $2.6 million , $3.9 million and $3.6 million , respectively), Criteo Ltd ( $7.7 million , $4.7 million and $4.7 million , respectively), Criteo China ( $0.7 million , $1.4 million and $3.7 million , respectively) and Criteo France ( $0.7 million , $0.6 million and $3.0 million , respectively). The main changes that occurred in 2016 relate to the recognition of deferred tax assets for Criteo Corp. tax losses and temporary differences in connection with the 3 -year tax plan ( $8.5 million ). In accordance with ASC 740 - Income taxes , no uncertain tax positions were identified as of December 31, 2016. The Company has various net operating loss carryforwards in the U.S. and China for $14.9 million and $3.6 million , respectively, which begin to expire in 2030 and 2019, respectively. The Company has net operating loss carryforwards in the United Kingdom of $4.8 million which have no expiration date. Current tax assets The total amount corresponds to prepayments of income taxes by Criteo do Brasil Ltda.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic Earnings Per Share We calculate basic earnings per share by dividing the net income for the period attributable to shareholders of the Parent by the weighted average number of shares outstanding. Year Ended December 31, 2014 2015 2016 (in thousands, except share data) Net income attributable to shareholders of Criteo S.A. $ 45,556 $ 59,553 $ 82,272 Weighted average number of shares outstanding 58,928,563 61,835,499 63,337,792 Basic earnings per share $ 0.77 $ 0.96 $ 1.30 Diluted Earnings Per Share We calculate diluted earnings per share by dividing the net income attributable to shareholders of the Parent by the weighted average number of shares outstanding plus any potentially dilutive shares not yet issued from share-based compensation plans (see note 19). There were no other potentially dilutive instruments outstanding as of December 31, 2014 , 2015 and 2016 . Consequently all potential dilutive effects from shares are considered. For each period presented, a contract to issue a certain number of shares (i.e. share option, share warrant, restricted share award or BSPCE contracts) is assessed as potentially dilutive, if it is “in the money” (i.e., the exercise or settlement price is inferior to the average market price). Year Ended December 31, 2014 2015 2016 (in thousands, except share data) Net income attributable to shareholders of Criteo S.A. $ 45,556 $ 59,553 $ 82,272 Weighted average number of shares outstanding of Criteo S.A. 58,928,563 61,835,499 63,337,792 Dilutive effect of : Restricted share awards — — 253,728 Share options and BSPCE 4,347,236 3,133,549 1,958,728 Share warrants 217,461 127,438 83,222 Weighted average number of shares outstanding used to determine diluted earnings per share 63,493,260 65,096,486 65,633,470 Diluted earnings per share $ 0.72 $ 0.91 $ 1.25 The weighted average number of securities that were anti-dilutive for diluted EPS for the periods presented but which could potentially dilute EPS in the future are as follows: Year Ended December 31, 2014 2015 2016 Restricted share awards — 273,896 396,086 Share options and BSPCE 1,288,977 968,734 509,442 Share warrants — 15,925 — Weighted average number of anti-dilutive securities excluded from diluted earnings per share 1,288,977 1,258,555 905,528

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Contingencies Changes in provisions during the presented periods are summarized below: Provision for employee- related litigation Provision for tax- related litigation Other provisions Total (in thousands) Balance at January 1, 2015 $ 781 $ 592 $ — $ 1,373 Charges 200 44 388 632 Provision used (487 ) — — (487 ) Provision released not used (186 ) (541 ) — (727 ) Currency translation adjustments (72 ) (51 ) — (123 ) Balance at January 1, 2016 $ 236 $ 44 $ 388 $ 668 Charges 671 — 166 837 Provision used (402 ) — (48 ) (450 ) Provision released not used — (44 ) (347 ) (391 ) Currency translation adjustments (20 ) — 10 (10 ) Balance at December 31, 2016 $ 485 $ — $ 169 $ 654 - of which current $ 485 $ — $ 169 $ 654 The amount of the provisions represent management’s best estimate of the future outflow. Provisions are mainly in relation to employee-related litigation and other provisions which consist of estimated restoration costs following the end of leases in 2015 and 2016. The remaining provision was for tax contingencies relating to a tax inspection covering the fiscal years 2008 and 2009, which released upon receipt of the tax notification as of December 31, 2015. Commitments and contingencies Operating Lease Arrangements Future payment obligations under non-cancellable operating leases as of December 31, 2016 are listed below: Less than 1 year 1 to 5 years 5 years + Total (in thousands) Minimum payments for property leases $ 33,655 $ 98,938 $ 49,551 $ 182,144 Minimum payments for hosting services 50,959 48,927 — 99,886 Minimum payments for other leases $ 4,197 $ 4,912 $ — $ 9,109 Operating Lease Expenses Operating lease expenses relating to our offices totaled $32.1 million , $23.6 million and $18.8 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. Operating lease expenses relating to hosting services totaled $42.0 million , $30.4 million , and $24.8 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. Revolving Credit Facilities, Credit Lines Facilities and Bank Overdrafts As mentioned in Note 14, we are party to three RCFs including one with BPI France, for which we can draw up to €1.0 million ( $1.1 million ), one with HSBC for which we can draw up to RMB 40.0 million ( $5.8 million ), and one with a syndicate of banks which allow us to draw up to €250.0 million ( $263.5 million ). As of December 31, 2016, €0.1 million ( $0.1 million ), RMB 30.0 million ( $4.3 million ), and $75.0 million had been drawn, respectively. All of these credit facilities are unsecured and contain customary events of default but do not contain any affirmative, financial or negative covenants, with the exception of the €250.0 million ( $263.5 million ) RCF which contains covenants, including compliance with a total net debt to adjusted EBITDA ratio and restrictions on incurring additional indebtedness. At December 31, 2016 , we were in compliance with the required leverage ratio. We are also party to short-term credit lines and overdraft facilities with HSBC plc, and LCL. We are authorized to draw up to a maximum of €9.4 million ( $9.9 million ) in the aggregate under the short-term credit lines and overdraft facilities. As of December 31, 2016 , we had not drawn on any of these facilities. Any loans or overdraft under these short-term facilities bear interest based on the one month EURIBOR rate or three month EURIBOR rate. As these facilities are exclusively short-term credit and overdraft facilities, our banks have the ability to terminate such facilities on short notice. Contingencies From time to time we may become involved in legal proceedings or be subject to claims arising in the ordinary course of our business. We are not presently a party to any legal proceedings that, if determined adversely to us, would individually or taken together have a material adverse effect on our business, results of operations, financial condition or cash flows. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related Parties	Related Parties During its meeting on December 17, 2015, the Board of Directors decided to separate the functions of Chairman of the Board and Chief Executive Officer. Effective January 1, 2016, Jean-Baptiste Rudelle became Executive Chairman and Eric Eichmann was appointed Chief Executive Officer. In the exercise of his responsibilities, Mr. Eichmann was assisted by Benoit Fouilland, Chief Financial Officer, and Romain Niccoli, Chief Product Officer. On October 26, 2016, Romain Niccoli resigned as Chief Product Officer, with effect from December 31, 2016. The Executive Officers as of December 31, 2016 were: • Jean-Baptiste Rudelle—Executive Chairman • Romain Niccoli—Chief Product Officer • Benoit Fouilland—Chief Financial Officer • Eric Eichmann—Chief Executive Officer Total compensation for the Executive Officers, including social contributions, is summarized in the following table: Year Ended December 31, 2014 2015 2016 (in thousands) Short-term benefits (1) $ (4,145 ) $ (3,067 ) $ (2,755 ) Long-term benefits (2) (241 ) (245 ) (194 ) Shared-based compensation (3,291 ) (4,594 ) (7,159 ) Total $ (7,677 ) $ (7,906 ) $ (10,108 ) (1) wages, bonuses and other compensations (2) pension defined benefit plan For the year ended December 31, 2016, 2015 and 2014, there were no material related party transactions.

Breakdown of Revenue and Non-Cu

Breakdown of Revenue and Non-Current Assets by Geographical Areas	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Breakdown of Revenue and Non-Current Assets by Geographical Areas	Breakdown of Revenue and Non-Current Assets by Geographical Areas The Company operates in the following three geographical markets: • Americas: North and South America; • EMEA: Europe, Middle-East and Africa; and • Asia-Pacific. The following tables disclose our consolidated revenue for each geographical area for each of the reported periods. Revenue by geographical area is based on the location of advertisers’ campaigns. Americas EMEA Asia-Pacific Total (in thousands) December 31, 2014 $ 303,436 $ 485,986 $ 198,827 $ 988,249 December 31, 2015 505,653 541,105 276,411 1,323,169 December 31, 2016 $ 730,873 $ 660,523 $ 407,750 $ 1,799,146 Revenue generated in France amounted to $115.4 million , $116.8 million and $132.2 million for the periods ended December 31, 2014 , 2015 and 2016 , respectively. Revenue generated in other significant countries where we operate is presented in the following table: Year Ended December 31, 2014 2015 2016 (in thousands) Americas United States $ 237,385 $ 419,742 $ 630,047 EMEA Germany 105,544 111,792 137,116 United Kingdom 90,315 107,071 115,053 Asia-Pacific Japan $ 154,798 $ 190,066 $ 285,959 Other Information For each reported period, non-current assets (corresponding to the net book value of tangible and intangible assets) are presented in the table below. The geographical information results from the locations of legal entities. Of which Of which Holding Americas United States EMEA Asia-Pacific Japan Total (in thousands) December 31, 2015 $ 48,160 $ 24,437 $ 23,332 $ 8,847 $ 17,508 $ 7,807 $ 98,952 December 31, 2016 $ 55,052 $ 43,308 $ 42,474 $ 7,132 $ 26,033 $ 8,965 $ 131,525

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company evaluated subsequent events that occurred after December 31, 2016 through the date of issuance of the Consolidated Financial Statements and determined that there are no significant events that require adjustments or disclosure in such Consolidated Financial Statements.

Principles and Accounting Met34

Principles and Accounting Methods (Policies)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Preparation The Consolidated Financial Statements have been prepared assuming a going concern and using the historical cost principle with the exception of certain assets and liabilities that are measured at fair value in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”). The categories concerned are detailed in the following notes.
Consolidation Methods	Consolidation Methods We have control over all our subsidiaries, and consequently they are all fully consolidated. Intercompany transactions and balances have been eliminated. The table below presents at each period’s end and for all entities included in the consolidation scope the following information: the country of incorporation and the percentage of voting rights and ownership interests.
Functional Currency and Translation of Financial Statements in Foreign Currency and Conversion of Foreign Currency Translation	Functional Currency and Translation of Financial Statements in Foreign Currency The Consolidated Financial Statements are presented in U.S. dollars, which differs from the functional currency of the Parent, being the Euro. The statements of financial position of consolidated entities having a functional currency different from the U.S. dollar are translated into U.S. dollars at the closing exchange rate (spot exchange rate at the statement of financial position date) and the statements of income, statements of comprehensive income and statements of cash flow of such consolidated entities are translated at the average period to date exchange rate. The resulting translation adjustments are included in equity under the caption “Accumulated other comprehensive income (loss)” in the Consolidated Statements of Changes in Shareholders' Equity. Conversion of Foreign Currency Transactions Foreign currency transactions are converted to U.S. dollars at the rate of exchange applicable on the transaction date. At period-end, foreign currency monetary assets and liabilities are converted at the rate of exchange prevailing on that date. The resulting exchange gains or losses are recorded in the Consolidated Statements of Income in “Other financial income (expense)” with the exception of exchange differences arising from monetary items that form part of the reporting entity’s net investment in a foreign operation which are recognized in other comprehensive income (loss); they will be recognized in profit or loss on disposal of the net investment.
Use of Estimates	Use of Estimates Our Consolidated Financial Statements are prepared in accordance with U.S. GAAP. The preparation of our Consolidated Financial Statements requires us to make estimates, assumptions and judgments that affect the reported amounts of assets, liabilities, revenue and expenses. We base our estimates and assumptions on historical experience and other factors that we believe to be reasonable under the circumstances. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates. The most significant areas that require management judgment and estimates relate to (1) the recognition of revenue and particularly, the determination as to whether revenue should be reported on a gross or a net basis; (2) the evaluation of our trade receivables and the recognition of a valuation allowance for doubtful accounts; (3) the recognition of our deferred tax assets considering the subsidiaries projected taxable profit within the next three years and the potential tax deduction upon future exercises of share-options in certain jurisdictions; (4) the recognition and measurement of goodwill and intangible assets and particularly costs capitalized in relation to our customized internal-use software; and (5) the measurement of share-based compensation.
Business Combinations	Business combinations We include the results of operations of the businesses that we acquire as of the acquisition date. We allocate the purchase price of our acquisitions to the assets acquired and liabilities assumed based on their estimated fair values. The excess of the purchase price over the fair values of these identifiable assets and liabilities is recorded as goodwill. Acquisition-related expenses are recognized separately from the business combination and are expensed as incurred.
Intangible Assets	Intangible Assets Acquired intangible assets are accounted for at acquisition cost, less accumulated amortization. Acquired intangible assets are primarily composed of software amortized on a straight-line basis over their estimated useful lives comprised between one and three years. Intangible assets are reviewed for impairment whenever events or changes in circumstances such as, but not limited to, significant declines in revenue, earnings or cash flows or material adverse changes in the business climate indicate that the carrying amount of an asset may be impaired. Costs related to customized internal-use software that have reached the development stage are capitalized. Capitalization of such costs begins when the preliminary project stage is complete and stops when the project is substantially complete and is ready for its intended purpose. In making this determination, several analyses for each phase were performed, including analysis of the feasibility, availability of resources, intention to use and future economic benefits. Amortization of these costs begins when assets are placed in service and is calculated on a straight-line basis over the assets’ useful lives estimated at three to five years. Our research and development efforts are focused on enhancing the performance of our solution and improving the efficiency of the services we deliver to our clients. All development costs, principally headcount-related costs, are expensed as incurred as management has determined that technological feasibility is reached shortly before our product is available for release to customers.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are accounted for at acquisition cost less cumulative depreciation and any impairment loss. Depreciation is calculated on a straight-line basis over the assets’ estimated useful lives as follows: Fixtures and fittings (mainly composed of leasehold improvements).................................. 5 to 10 years Furniture and equipment (servers and IT equipment in data centers and office equipment)............ 1 to 5 years Leasehold improvements are depreciated over their useful life or over the lease term, whichever is shorter. The gains and losses on disposal of assets are determined by comparing selling price with the net book value of the disposed asset.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill represents the excess of the aggregate purchase price paid over the fair value of the net tangible and intangible assets acquired. Intangible assets that are not considered to have an indefinite useful life are amortized over their useful lives. The Company evaluates the estimated remaining useful lives of purchased intangible assets and whether events or changes in circumstances warrant a revision to the remaining periods of amortization. Goodwill is not amortized and is tested for impairment at least annually or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that it operates as a single reporting unit and has selected December 31 as the date to perform its annual impairment test. In the impairment assessment of its goodwill, the Company performs a two-step impairment test, which involves assumptions regarding estimated future cash flows to be derived from the Company. If these estimates or their related assumptions change in the future, the Company may be required to record impairment for these assets. The first step of the impairment test involves comparing the fair value of the reporting unit to its net book value, including goodwill. If the net book value exceeds its fair value, then the Company would perform the second step of the goodwill impairment test to determine the amount of the impairment loss. The impairment loss to be recognized would be calculated by comparing the implied fair value of the Company to its net book value. In calculating the implied fair value of the Company’s goodwill, the fair value of the Company would be allocated to all of the other assets and liabilities based on their fair values. The excess of the fair value of the Company over the amount assigned to its other assets and liabilities is the implied fair value of goodwill. An impairment loss would be recognized in the Consolidated Statement of Income when the carrying amount of goodwill exceeds its implied fair value. With respect to intangible assets, acquired intangible assets are accounted for at acquisition cost less cumulative amortization and any impairment loss. Acquired intangible assets are amortized over their estimated useful lives of one to five years on a straight-line method. Intangible assets are reviewed for impairment whenever events or changes in circumstances such as, but not limited to, significant declines in revenue, earnings or cash flows or material adverse changes in the financial and economic environment indicate that the carrying amount of an asset may be impaired.
Property, Plant and Equipment and Impairment of Long-lived Assets	Property, Plant and Equipment and Impairment of Long-lived Assets The Company periodically reviews long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset is impaired or the estimated useful life is no longer appropriate. If indicators of impairment exist and the undiscounted projected cash flows associated with an asset are less than the carrying amount of the asset, an impairment loss is recorded to write the asset down to its estimated fair value. Fair value is estimated based on discounted future cash flows.
Leases	Leases The Company leases various facilities under agreements accounted for as operating leases. For leases that contain escalation or rent concessions provisions, management recognizes rent expense during the lease term on a straight-line basis over the term of the lease. The difference between rent paid and straight-line rent expense is recorded as a deferred rent liability in the accompanying Consolidated Statement of Financial Position. Assets held under capital leases are recorded at the lower of the net present value of the minimum lease payments or at the fair value of the leased asset at the inception of the lease. Amortization expense is computed using the straight-line method over the shorter of the estimated useful life of the asset or the period of the related lease. Principal payments on capital lease obligations are recorded as reduction of capital lease liability in the accompanying consolidated balance sheets, and interest payments are recorded as interest expense which is included in financial income (expense), in the accompanying Consolidated Statements of Operations
Financial Assets and Liabilities, Excluding Derivative Financial Instruments	Financial Assets and Liabilities, Excluding Derivative Financial Instruments Financial assets, excluding cash and cash equivalents, consist exclusively of loans and receivables. Loans and receivables are non-derivative financial assets with a payment, which is fixed or can be determined, not listed on an active market. They are included in current assets, except those that mature more than twelve months after the reporting date. Loans are measured at amortized cost using the effective interest method. The recoverable amount of loans and advances is estimated whenever there is an indication that the asset may be impaired and at least on each reporting date. If the recoverable amount is lower than the carrying amount, an impairment loss is recognized in the Consolidated Statements of Income. Financial liabilities are initially recorded at their fair value at the transaction date. Subsequently they are measured at amortized cost using the effective interest method. We carry our accounts receivable at net realizable value. On a periodic basis, our management evaluates our accounts receivable and determines whether to provide an allowance or if any accounts should be written down and charged to expense as a bad debt. The evaluation is based on, among other factors, a past history of collections, current credit conditions, the ageing of the receivable and a past history of write downs. A receivable is considered past due if we have not received payments based on agreed-upon terms. A higher default rate than estimated or a deterioration in our clients’ creditworthiness could have an adverse impact on our future results. Allowances for doubtful accounts on trade receivables are recorded in “sales and operations expenses” in our Consolidated Statements of Income. We generally do not require any security or collateral to support our receivables.
Derivative Financial Instruments	Derivative financial instruments We buy and sell derivative financial instruments (mainly put, forward buying and selling) in order to manage and reduce our exposure to the risk of exchange rate fluctuations. We deal only with major financial institutions. Under the ASC 815 – Derivatives and hedging , financial instruments may only be classified as hedges when we can demonstrate and document the effectiveness of the hedging relationship at inception and throughout the life of the hedge. The effectiveness of the hedge is determined by reference to changes in the value of the derivative instrument and the hedged item. The ratio must remain within 80% to 125% . Derivative financial instruments are recognized in the balance sheet at their market value on the reporting date in financial current assets or liabilities. Changes in fair value are recorded as follows: • cash flow hedges : the portion of the gain or loss on the financial instrument that is determined to be an effective hedge is recorded directly to equity. The ineffective portion is recorded to the income statement; • fair value hedges and financial instruments not designated as hedges : changes in fair value are recorded to the income statement.
Fair Value Measurements	Fair value measurements In accordance with ASC 820 – Fair value measurement , financial instruments are presented in three categories based on a hierarchical method used to determine their fair value : (i) level 1: fair value calculated using quoted prices in an active market for identical assets and liabilities; (ii) level 2: fair value calculated using valuation techniques based on observable market data such as prices of similar assets and liabilities or parameters quoted in an active market; (iii) level 3: fair value calculated using valuation techniques based wholly or partially on unobservable inputs such as prices in an active market or a valuation based on multiples for unlisted companies. The Company's valuation techniques used to measure the fair value of money market funds and certain short term investments were derived from quoted prices in active markets. The valuation techniques used to measure the fair value of the Company's financial liabilities and all other financial instruments, all of which have counterparties with high credit ratings, were valued based on quoted market prices or model-driven valuations using inputs derived from or corroborated by observable market data.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash includes cash on hand and demand deposits with banks. Cash equivalents include short-term, highly liquid investments, with a remaining maturity at the date of purchase of three months or less for which the risk of changes in value is considered to be insignificant. Demand deposits therefore meet the definition of cash equivalents. Cash equivalents are measured at fair value using level 1 for cash at hand and money market funds using quoted prices, and any changes are recognized in the Consolidated Statements of Income.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and accounts receivable. The Company’s cash and cash equivalents are held at major financial institutions that the Company's management has assessed to be of high credit quality. The Company has not experienced any losses in such accounts. The Company mitigates its credit risk with respect to accounts receivable by performing credit evaluations and monitoring agencies' and advertisers' accounts receivable balances. As of December 31, 2016 and 2015 no customer accounted for 10% or more of accounts receivable. During the years ended December 31, 2016 , 2015 and 2014 , no single customer represented 10% or more of revenue.
Employee Benefits	Employee Benefits Depending on the laws and practices of the countries in which we operate, employees may be entitled to compensation when they retire or to a pension following their retirement. For state-managed plans and other defined contribution plans, we recognize them as expenses when they become payable, our commitment being limited to our contributions. The liability with respect to defined benefit plans is estimated using the following main assumptions: • discount rate; • future salary increases; and • employee turnover. Service costs are recognized in profit or loss and are allocated by function. Actuarial gains and losses are recognized in other comprehensive income and subsequently amortized into the income statement over a specified period, which is generally the expected average remaining service period of the employees participating in the plan. Actuarial gains and losses arise as a result of changes in actuarial assumptions or experience adjustments (differences between the previous actuarial assumptions and what has actually occurred).
Contingencies	Contingencies We recognize contingencies in accordance with ASC 450 - Contingencies , if the following two conditions are met: • information available before the financial statements are issued indicates that it is probable that an asset had been impaired or a liability had been incurred at the date of the financial statements; • the amount of loss can be reasonably estimated With respect to litigation and claims that may result in a provision to be recognized, we exercise significant judgment in measuring and recognizing provisions or determining exposure to contingent liabilities that are related to pending litigation or other outstanding claims. These judgment and estimates are subject to change as new information becomes available.
Revenue Recognition	Revenue Recognition We sell personalized display advertisements featuring product-level recommendations either directly to clients or to advertising agencies, which we collectively refer to as our clients, and generate revenue when a user clicks on the banner ad. We generally price our advertising campaigns on a cost per click (“CPC”) model based on the number of clicks generated by users on each advertisement we deliver in our advertising campaigns. Revenue is recognized when the related services are delivered based on the specific terms of the contract, which are commonly based on specified CPCs and related campaign budgets. We recognize revenue when four basic criteria are met: (1) persuasive evidence exists of an arrangement with the client reflecting the terms and conditions under which the services will be provided; (2) services have been provided or delivery has occurred; (3) the fee is fixed or determinable; and (4) collection is reasonably assured. Collectability is assessed based on a number of factors, including the creditworthiness of a client, the size and nature of a client’s website and transaction history. Amounts billed or collected in excess of revenue recognized are included as deferred revenue. An example of this deferred revenue would be arrangements where clients request or are required by us to pay in advance of delivery. We recognize revenue from the delivery of display advertisements in the period in which the display advertisements are delivered. Specifically, we recognize revenue for display ad delivery through our solution once the consumer clicks on the personalized banner displayed by us on the client’s website for CPC ad campaigns. For CPC ad campaigns, sales are valued at the fair value of the amount received. Rebates and discounts granted to clients, along with free or extended advertising campaigns, are recorded as a deduction from revenue. Essentially all of our revenue in each of 2014 , 2015 and 2016 was derived from advertising campaigns sold on a CPC basis. In the specific case of Criteo Predictive Search, we recognize revenue when users exposed to the Google Shopping campaigns of our clients generate a sale on the digital property of our clients after clicking on the shopping advertisements displayed on Google. Our revenue for Criteo Predictive Search is a percentage of the sales generated by a client's Google Shopping campaigns, which means we only get paid for completed sales. The determination of whether revenue should be reported on a gross or net basis is based on an assessment of whether we are acting as the principal or an agent in our transactions. In determining whether we act as the principal or an agent, we follow the accounting guidance for principal-agent considerations. The determination of whether we are acting as a principal or an agent in a transaction involves judgment and is based on an evaluation of the terms of each arrangement. While none of the factors individually are considered presumptive or determinative, because we are the primary obligor and are responsible for (1) identifying and contracting with third-party clients; (2) establishing the selling prices of the display advertisements sold; (3) performing all billing and collection activities, including retaining credit risk; and (4) bearing sole responsibility for fulfillment of the advertising and the inventory risk, we act as the principal in these arrangements and therefore report revenue earned and costs incurred related to these transactions on a gross basis. With Criteo Predictive Search, we do not purchase search inventory ourselves; our advertiser clients have direct access to Google Shopping inventory and buy such inventory themselves. As a result of not incurring inventory costs related to these transactions, we act as an agent for our clients with respect to these transactions. Consequently, revenue for Criteo Predictive Search is reported on a net basis. In the specific case of Criteo Sponsored Products, we generally act as principal and as a result, we report revenue earned and costs incurred related to these transactions on a gross basis. When we do not (i) set the price, (ii) select the publisher site the advertisement is placed on, (iii) take responsibility for the acceptability of the service and (iv) bear the credit risk, we report revenue earned and costs incurred related to these transactions on a net basis.
Cost of Revenue	Cost of Revenue Our cost of revenue primarily includes traffic acquisition costs and other cost of revenue. Traffic Acquisition Costs . Traffic acquisition costs consist primarily of purchases of impressions from publishers on a CPM basis. We purchase impressions directly from publishers or third-party intermediaries, such as advertisement exchanges. We recognize cost of revenue on a publisher by publisher basis as incurred. Costs owed to publishers but not yet paid are recorded in our Consolidated Statements of Financial Position as trade payables and other current liabilities. Under our current agreements with our publishers, we only commit to purchase a defined volume of impressions from any given publisher to the extent that a pre-determined click through rate, or CTR, is reached. If the publisher fails to reach the targeted volume of impressions, we can either terminate the agreement or reduce our commitment to buy impressions accordingly. For Criteo Sponsored Products, we pay for the inventory of our ecommerce retailer partners on a revenue sharing basis, effectively paying the retailers a portion of the click-based revenue generated by user clicks on the sponsored products advertisements displaying the products of our brand manufacturer clients. For Criteo Predictive Search, we do not purchase search inventory ourselves; our advertiser clients have direct access to Google Shopping inventory, and we optimize the bidding price for such inventory on behalf of the clients to maximize the sales generated by shopping campaigns. Other Cost of Revenue . Other cost of revenue includes expenses related to third-party hosting fees, depreciation of data center equipment and data purchased from third parties. The Company does not build or operate its own data centers and none of its Research and Development employments are dedicated to revenue generating activities. As a result, we do not include the costs of such personnel in other cost of revenue.
Share-Based Compensation	Share-Based Compensation Shares, employee share options and employee and non-employee warrants are primarily awarded to our employees or directors. As required by ASC 718 – Compensation – Stock Compensation , these awards are measured at their fair value on the date of grant. The fair value is calculated with the most relevant formula regarding the settlement and the conditions of each plan. The fair value is recorded in personnel expenses (allocated by function in the Consolidated Statements of Income) on a straight-line basis over each milestone composing the vesting period with a corresponding increase in shareholders’ equity. At each closing date, we re-examine the number of options likely to become exercisable. If applicable, the impact of the review of the estimate is recognized in the Consolidated Statements of Income with a corresponding adjustment in equity.
Income Taxes	Income Taxes We elected to classify the French business tax, Cotisation sur la Valeur Ajoutée des Entreprises (“CVAE”), as an income tax in compliance with ASC 740— Income Taxes (“ASC 740”). The French Research Tax Credit, Crédit d’Impôt Recherche (“CIR”), is a French tax incentive to stimulate research and development (“R&D”). Generally, the CIR offsets the income tax to be paid and the remaining portion (if any) can be refunded at the end of a three-fiscal year period. The CIR is calculated based on the claimed volume of eligible R&D expenditures by us. As a result, the CIR is presented as a deduction to “research and development expenses” in the Consolidated Statements of Income, as the CIR is not within the scope of ASC 740. We have exclusively claimed R&D performed in France for purposes of the CIR. Income taxes are accounted for under the asset and liability method of accounting. Deferred taxes are recorded on all temporary differences between the financial reporting and tax bases of assets and liabilities, and on tax losses, using the liability method. Differences are defined as temporary when they are expected to reverse within a foreseeable future. We may only recognize deferred tax assets if, based on the projected taxable incomes within the next three years, we determine that it is probable that future taxable profit will be available against which the unused tax losses and tax credits can be utilized. As a result, the measurement of deferred income tax assets is reduced, if necessary, by a valuation allowance for any tax benefits which are not expected to be realized. If future taxable profits are considerably different from those forecasted that support recording deferred tax assets, we will have to revise downwards or upwards the amount of deferred tax assets, which would have a significant impact on our financial results. This determination requires many estimates and judgments by our management for which the ultimate tax determination may be uncertain. In accordance with ASC 740, tax assets and liabilities are not discounted. Amounts recognized in the Consolidated Financial Statements are calculated at the level of each tax entity included in the consolidation scope. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in the period that such tax rate changes are enacted.
Uncertain Tax Positions	Uncertain Tax Positions The Company follows the guidance of ASC 740, which prescribes a more likely than not threshold for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. This Interpretation also provides guidance on recognition of income tax assets and liabilities, classification of current and deferred income tax assets and liabilities, accounting for interest and penalties associated with tax positions, accounting for income taxes in interim periods, and income tax disclosures.
Operating Segments	Operating Segments In accordance with ASC 280 – Segment reporting , segment information reported is built on the basis of internal management data used for performance analysis of businesses and for the allocation of resources (management approach). An operating segment is a component of the Company for which separate financial information is available that is evaluated regularly by our Chief Decision Maker in deciding how to allocate resources and assessing performance. Our chief operating decision-maker is our CEO. The CEO reviews consolidated data for revenue, revenue excluding traffic acquisition costs (revenue ex-TAC) and Adjusted EBITDA (earnings before financial income (expense), income taxes, depreciation and amortization, adjusted to eliminate the impact of equity awards compensation expense, pension service costs, acquisition-related costs and deferred price consideration ) for the purposes of allocating resources and evaluating financial performance. We have concluded that our operations constitute one operating and reportable segment.
Earnings Per Share	Earnings Per Share In accordance with ASC 260— Earnings Per Share , basic earnings per share (“EPS”) are calculated by dividing the net income attributable to shareholders of the Parent by the weighted average number of shares outstanding. The weighted average number of shares outstanding is calculated according to movements in share capital. In addition, we calculate diluted earnings per share by dividing the net income attributable to shareholders of the Parent company, Criteo S.A. by the weighted average number of shares outstanding plus any potentially dilutive shares not yet issued.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09), which amends the existing accounting standards for revenue recognition. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , which delays the effective date of ASU 2014-09 by one year. The FASB also agreed to allow entities to choose to adopt the standard as of the original effective date. In March 2016, the FASB issued Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) (ASU 2016-08) which clarifies the implementation guidance on principal versus agent considerations. The guidance includes indicators to assist an entity in determining whether it controls a specified good or service before it is transferred to the customers. The new revenue recognition standard will be effective for the Company in the first quarter of 2018, with the option to adopt it in the first quarter of 2017. We currently anticipate adopting the new standard effective January 1, 2018. The new standard also permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the modified retrospective method). We currently anticipate adopting the standard using the modified retrospective method. While we are still in the process of completing our analysis on the impact this guidance will have on our Consolidated Financial Statements and related disclosures, the more significant changes that we have identified to date relate to the gross versus net presentation of our consolidated revenue. Upon adoption of ASU 2014-09, we may be required to report, on a net basis, a portion of the revenue derived from Criteo Sponsored Products. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases (Topic 842) (ASU 2016-02), which generally requires companies to recognize operating and financing lease liabilities and corresponding right-of-use assets on the balance sheet for operating leases with terms of more than 12 months, in addition to those currently recorded. This guidance will be effective for us in the first quarter of 2019 on a modified retrospective basis and early adoption is permitted. We are still evaluating the effect that this guidance will have on our Consolidated Financial Statements and related disclosures. In October 2016, the FASB issued Accounting Standards Update No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers Other than Inventory (ASU 2016-16), which requires companies to recognize the income-tax consequences of an intra-entity transfer of an asset other than inventory. This guidance will be effective for us in the first quarter of 2018, with the option to adopt it in the first quarter of 2017. We currently anticipate adopting the new standard effective January 1, 2018, and do not expect the standard to have a material impact on our Consolidated Financial Statements. In November 2016, the FASB issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance will be effective for us in the first quarter of 2018 and early adoption is permitted. We are still evaluating the effect that this guidance will have on our Consolidated Financial Statements and related disclosures. Other accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s Consolidated Financial Statements upon adoption.

Principles and Accounting Met35

Principles and Accounting Methods (Tables)	12 Months Ended
	Dec. 31, 2016
Accounting Policies [Abstract]
Schedule of Ownership Interests	The table below presents at each period’s end and for all entities included in the consolidation scope the following information: the country of incorporation and the percentage of voting rights and ownership interests. 2015 2016 Country Voting rights Ownership Interest Voting rights Ownership Interest Consolidation Method Parent company Criteo S.A France 100 % 100 % 100 % 100 % Parent company French subsidiaries Criteo France SAS France 100 % 100 % 100 % 100 % Fully consolidated Criteo Finance SAS France - - 100 % 100 % Fully consolidated Foreign subsidiaries Criteo Ltd United Kingdom 100 % 100 % 100 % 100 % Fully consolidated Criteo Corp United States 100 % 100 % 100 % 100 % Fully consolidated Criteo Gmbh Germany 100 % 100 % 100 % 100 % Fully consolidated Criteo KK Japan 66 % 66 % 66 % 66 % Fully consolidated Criteo Do Brasil LTDA Brazil 100 % 100 % 100 % 100 % Fully consolidated Criteo BV The Netherlands 100 % 100 % 100 % 100 % Fully consolidated Criteo Pty Australia 100 % 100 % 100 % 100 % Fully consolidated Criteo Srl Italy 100 % 100 % 100 % 100 % Fully consolidated Criteo Advertising (Beijng) Co. Ltd China 100 % 100 % 100 % 100 % Fully consolidated Criteo Singapore Pte. Ltd. Singapore 100 % 100 % 100 % 100 % Fully consolidated Criteo LLC Russia 100 % 100 % 100 % 100 % Fully consolidated Criteo Europa S.L. Spain 100 % 100 % 100 % 100 % Fully consolidated Criteo Espana S.L. Spain 100 % 100 % 100 % 100 % Fully consolidated Criteo Canada Corp. Canada 100 % 100 % 100 % 100 % Fully consolidated Criteo Reklamcılık Hizmetleri ve Ticaret Anonim Şirketi Turkey 100 % 100 % 100 % 100 % Fully consolidated Criteo MEA FZ-LLC United Arab Emirates 100 % 100 % 100 % 100 % Fully consolidated Criteo India Private Ltd. India - - 100 % 100 % Fully consolidated HookLogic, Inc. United States - - 100 % 100 % Fully consolidated HookLogic Ltd United Kingdom - - 100 % 100 % Fully consolidated Hooklogic Brasil Solucoes EM Tecnología Ltda Brazil - - 100 % 100 % Fully consolidated

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	In allocating the purchase price for the transaction, the Company recorded the following (in millions): Amounts recognized as of Acquisition Date (in millions) Cash and cash equivalents $ 19.7 Trade receivables, net of allowances 29.2 Other current assets 1.0 Property, plant and equipment, net 1.3 Identifiable intangible assets 84.4 Non-current financial assets 0.3 Trade payables (38.7 ) Financial liabilities - current portion (7.4 ) Other taxes (0.5 ) Employee-related payables (1.4 ) Other current liabilities (3.1 ) Total identifiable net assets 84.8 Goodwill 165.3 Total fair value of consideration transferred $ 250.1
Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination	The following table summarizes the amounts and useful lives assigned to identified intangible assets : Weighted-Average Useful Lives (Years) Amounts recognized as of Acquisition Date (in millions) Technology 3-5 years 24.4 Customer relationships 5-9 years $ 60.0 Total identifiable intangible assets acquired $ 84.4

Categories of Financial Asset37

Categories of Financial Assets and Financial Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of financial assets	The following schedules disclose our financial assets categories for the presented periods: Year Ended December 31, 2015 Carrying Value Loans and receivables Fair value (in thousands) Cash and cash equivalents $ 353,537 $ — $ 353,537 Trade receivables, net of allowances 261,581 261,581 $ 261,581 Other taxes 29,552 29,552 $ 29,552 Other current assets 16,030 16,030 $ 16,030 Financial assets 17,184 17,184 $ 17,184 Total $ 677,884 $ 324,347 $ 677,884 Year Ended December 31, 2016 Carrying Value Loans and receivables Fair value (in thousands) Cash and cash equivalents $ 270,317 $ — $ 270,317 Trade receivables, net of allowances 397,244 397,244 $ 397,244 Other taxes 52,942 52,942 $ 52,942 Other current assets 19,340 19,340 $ 19,340 Financial assets 17,029 17,029 $ 17,029 Total $ 756,872 $ 486,555 $ 756,872
Schedules of Concentration of Risk, by Risk Factor	For each period presented, the aging of trade receivables and allowances for doubtful accounts is as follows: Year Ended December 31, 2015 2016 Gross value % Allowance % Gross value % Allowance % (in thousands) (in thousands) (in thousands) (in thousands) Not yet due $ 193,603 72.2 % $ — — % $ 265,600 65.0 % $ — — % 0 - 30 days $ 53,803 20.1 % $ — — % $ 92,163 22.5 % $ (49 ) 0.4 % 31 - 60 days $ 8,287 3.1 % $ — — % $ 19,747 4.8 % $ (182 ) 1.6 % 61 - 90 days $ 2,574 1.0 % $ (2 ) — % $ 6,055 1.5 % $ (191 ) 1.6 % > 90 days $ 9,578 3.6 % $ (6,262 ) 100.0 % $ 25,277 6.2 % $ (11,176 ) 96.4 % Total $ 267,845 100.0 % $ (6,264 ) 100.0 % $ 408,842 100.0 % $ (11,598 ) 100.0 % The maximum exposure to credit risk at the end of each reported period is represented by the carrying amount of financial assets, and summarized in the following table: Year Ended December 31, 2015 2016 (in thousands) Cash and cash equivalents $ 353,537 $ 270,317 Trade receivables, net of allowances 261,581 397,244 Other taxes 29,552 52,942 Other current assets 16,030 19,340 Non-current financial assets 17,184 17,029 Total $ 677,884 $ 756,872
Schedule of financial liabilities	Financial Liabilities Year Ended December 31, 2015 Carrying Value Fair value (in thousands) Trade payables $ 246,382 $ 246,382 Other taxes 30,463 30,463 Employee - related payables 42,275 42,275 Other current liabilities 15,531 15,531 Financial liabilities 10,428 10,428 of which derivative financial instruments 553 553 Total $ 345,079 $ 345,079 Year Ended December 31, 2016 Carrying Value Fair value (in thousands) Trade payables $ 365,788 $ 365,788 Other taxes 44,831 44,831 Employee - related payables 55,874 55,874 Other current liabilities 30,221 30,221 Financial liabilities 85,580 85,580 of which derivative financial instruments 1,968 $ 1,968 Total $ 582,294 $ 582,294

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	12 Months Ended
	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	The following table presents for each reported period, the breakdown of cash and cash equivalents: Year Ended December 31, 2015 2016 (in thousands) Money market funds $ 54,188 $ 31,688 Interest-bearing bank deposits 114,127 88,091 Cash and cash equivalents 185,222 150,538 Total Cash and cash equivalents $ 353,537 $ 270,317
Schedule of Financial Liabilities and Cash and Cash Equivalents Allocation by Currency	The following table shows the allocation by currency of our financial liabilities and cash and cash equivalents: Currency Carrying value EUR GBP USD CNY JPY KRW Other (in thousands) Borrowings $ 82,921 $ 3,289 $ — $ 75,253 $ 4,379 $ — $ — $ — Other financial liabilities 691 450 — 241 — — — — Financial derivatives 1,968 1,968 — — — — — — Financial liabilities 85,580 5,707 — 75,494 4,379 — — — Cash and cash equivalents $ 270,317 $ 197,997 $ 2,887 $ 29,636 $ 3,074 $ 17,316 $ 2,531 $ 16,876

Trade Receivables (Tables)

Trade Receivables (Tables)	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Schedules of trade receivables net book value and Changes in allowance for doubtful accounts	The following table shows the breakdown in trade receivables net book value for the presented periods: Year Ended December 31, 2015 2016 (in thousands) Trade accounts receivables $ 267,845 $ 408,842 (Less) Allowance for doubtful accounts (6,264 ) (11,598 ) Net book value at end of period $ 261,581 $ 397,244 Changes in allowance for doubtful accounts are summarized below: Year Ended December 31, 2014 2015 2016 (in thousands) Balance at beginning of period $ (2,529 ) $ (3,930 ) $ (6,264 ) Provision for doubtful accounts (2,248 ) (2,660 ) (9,898 ) Reversal of provision 910 — 4,464 Change in consolidation scope (450 ) (99 ) (221 ) Currency translation adjustment 387 425 321 Balance at end of period $ (3,930 ) $ (6,264 ) $ (11,598 )

Other Current Assets (Tables)

Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of other current assets net book value	The following table shows the breakdown in other current assets net book value for the presented periods: Year Ended December 31, 2015 2016 (in thousands) Prepayments to suppliers $ 2,774 $ 2,439 Employee-related receivables 94 97 Taxes receivables 29,552 52,942 Other debtors 3,687 3,166 Prepaid expenses 9,475 13,638 Gross book value at end of period 45,582 72,282 Net book value at end of period $ 45,582 $ 72,282

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Changes in net book value during the presented periods are summarized below: Fixtures and fittings Furniture and equipment Construction in Progress Total (in thousands) Net book value at January 1, 2015 $ 2,501 $ 47,391 $ 2,347 $ 52,239 Additions to tangible assets 13,408 50,849 3,990 68,247 Disposal of tangible assets (53 ) (48 ) — (101 ) Depreciation expense (1,840 ) (32,487 ) — (34,327 ) Change in consolidation scope 31 87 — 118 Currency translation adjustment (488 ) (2,936 ) (270 ) (3,694 ) Transfer into service 784 677 (1,461 ) — Net book value at December 31, 2015 14,343 63,533 4,606 82,482 Gross book value at end of period 15,948 125,968 4,606 146,522 Accumulated depreciation and impairment at end of period (1,605 ) (62,435 ) — (64,040 ) Net book value at January 1, 2016 14,343 63,533 4,606 82,482 Additions to tangible assets 6,188 57,866 11,976 76,030 Disposal of tangible assets net of accumulated depreciation — (8 ) — (8 ) Depreciation expense (4,496 ) (43,665 ) — (48,161 ) Change in consolidation scope 85 405 — 490 Currency translation adjustment (499 ) (1,665 ) (88 ) (2,252 ) Transfer into service 2,544 1,283 (3,827 ) — Net book value at December 31, 2016 $ 18,165 $ 77,749 $ 12,667 $ 108,581 Gross book value at end of period 24,200 179,025 12,667 215,892 Accumulated depreciation and impairment at end of period (6,035 ) (101,276 ) — (107,311 )

Intangible assets (Tables)

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Indefinite-Lived Intangible Assets	Changes in net book value during the presented periods are summarized below: Software Technology and customer relationships Construction in Progress Total (in thousands) Net book value at January 1, 2015 $ 5,122 $ 7,356 $ 343 $ 12,821 Additions to intangible assets 5,645 554 1,172 7,371 Amortization expense (3,631 ) (6,604 ) — (10,235 ) Change in consolidation scope 1 7,800 — 7,801 Currency translation adjustment (570 ) (666 ) (52 ) (1,288 ) Transfer into service 314 — (314 ) — Net book value at December 31, 2015 6,881 8,440 1,149 16,470 Gross book value at end of period 15,863 18,538 1,149 35,550 Accumulated depreciation and impairment at end of period (8,982 ) (10,098 ) — (19,080 ) Net book value at January 1, 2016 6,881 8,440 1,149 16,470 Additions to intangible assets 7,972 553 — 8,525 Amortization expense (3,449 ) (4,969 ) — (8,418 ) Change in consolidation scope 3 86,230 788 87,021 Currency translation adjustment (455 ) (185 ) (14 ) (654 ) Transfer into service 435 594 (1,029 ) — Net book value at December 31, 2016 $ 11,387 $ 90,663 $ 894 $ 102,944 Gross book value at end of period 22,770 106,328 894 129,992 Accumulated depreciation and impairment at end of period (11,383 ) (15,665 ) — (27,048 )
Schedule of Finite-Lived Intangible Assets	Changes in net book value during the presented periods are summarized below: Software Technology and customer relationships Construction in Progress Total (in thousands) Net book value at January 1, 2015 $ 5,122 $ 7,356 $ 343 $ 12,821 Additions to intangible assets 5,645 554 1,172 7,371 Amortization expense (3,631 ) (6,604 ) — (10,235 ) Change in consolidation scope 1 7,800 — 7,801 Currency translation adjustment (570 ) (666 ) (52 ) (1,288 ) Transfer into service 314 — (314 ) — Net book value at December 31, 2015 6,881 8,440 1,149 16,470 Gross book value at end of period 15,863 18,538 1,149 35,550 Accumulated depreciation and impairment at end of period (8,982 ) (10,098 ) — (19,080 ) Net book value at January 1, 2016 6,881 8,440 1,149 16,470 Additions to intangible assets 7,972 553 — 8,525 Amortization expense (3,449 ) (4,969 ) — (8,418 ) Change in consolidation scope 3 86,230 788 87,021 Currency translation adjustment (455 ) (185 ) (14 ) (654 ) Transfer into service 435 594 (1,029 ) — Net book value at December 31, 2016 $ 11,387 $ 90,663 $ 894 $ 102,944 Gross book value at end of period 22,770 106,328 894 129,992 Accumulated depreciation and impairment at end of period (11,383 ) (15,665 ) — (27,048 )
Schedule of estimated future amortization expense related to intangible assets	As of December 31, 2016 , expected amortization expense for intangible assets other than intangible assets recognized in conjunction with the HookLogic acquisition (refer to Note 3) for the next five years is as follows (in thousands): Software Technology and customer relationships Total 2017 $ 5,116 $ 2,709 $ 7,825 2018 4,321 2,411 6,732 2019 2,218 436 2,654 2020 586 — 586 2021 11 — 11 Total $ 12,252 $ 5,556 $ 17,808

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Goodwill (in thousands) Balance at January 1, 2015 $ 27,856 Additions to goodwill 16,695 Currency translation adjustment (2,578 ) Balance at December 31, 2015 41,973 Additions to goodwill 169,197 Currency translation adjustment (1,752 ) Balance at December 31, 2016 $ 209,418

Contingencies (Tables)

Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Changes in provisions for contingencies	Changes in provisions during the presented periods are summarized below: Provision for employee- related litigation Provision for tax- related litigation Other provisions Total (in thousands) Balance at January 1, 2015 $ 781 $ 592 $ — $ 1,373 Charges 200 44 388 632 Provision used (487 ) — — (487 ) Provision released not used (186 ) (541 ) — (727 ) Currency translation adjustments (72 ) (51 ) — (123 ) Balance at January 1, 2016 $ 236 $ 44 $ 388 $ 668 Charges 671 — 166 837 Provision used (402 ) — (48 ) (450 ) Provision released not used — (44 ) (347 ) (391 ) Currency translation adjustments (20 ) — 10 (10 ) Balance at December 31, 2016 $ 485 $ — $ 169 $ 654 - of which current $ 485 $ — $ 169 $ 654

Other Current Liabilities (Tabl

Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Other current liabilities	Other current liabilities are presented in the following table: Year Ended December 31, 2015 2016 (in thousands) Clients' prepayments $ 6,244 $ 9,176 Employee-related payables 42,275 55,874 Taxes payable 30,463 44,831 Accounts payable relating to capital expenditures 8,037 15,484 Other creditors 1,091 2,440 Deferred revenue 159 3,121 Total $ 88,269 $ 130,926

Financial Liabilities (Tables)

Financial Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of changes in current and non-current financial liabilities	The changes in current and non-current financial liabilities during the periods ended December 31, 2015 and December 31, 2016 are illustrated in the following schedules: As of December 31, 2014 New borrowings Repayments Liabilities assumed in connection with business combinations Other (1) Currency translation adjustment As of December 31, 2015 (in thousands) Borrowings $ 8,007 $ 4,023 $ (8,716 ) $ 1,796 $ 1,599 $ (736 ) $ 5,973 Financial liabilities relating to finance leases 282 — (258 ) — 24 (25 ) 23 Other financial liabilities 488 — (1,000 ) 1,000 174 (54 ) 608 Financial derivatives 743 — — — (116 ) (75 ) 552 Financial liabilities - current portion 9,520 4,023 (9,974 ) 2,796 1,681 (890 ) 7,156 Borrowings 5,044 — — — (1,275 ) (497 ) 3,272 Financial liabilities relating to finance leases 25 — — — (24 ) (1 ) — Other financial liabilities 191 — — — (174 ) (17 ) — Financial liabilities - non current portion 5,260 — — — (1,473 ) (515 ) 3,272 Borrowings 13,051 4,023 (8,716 ) 1,796 324 (1,233 ) 9,245 Financial liabilities relating to finance leases 307 — (258 ) — — (26 ) 23 Other financial liabilities 679 — (1,000 ) 1,000 — (71 ) 608 Financial derivatives 743 — — — (116 ) (75 ) 552 Total $ 14,780 $ 4,023 $ (9,974 ) $ 2,796 $ 208 $ (1,405 ) $ 10,428 (1) Includes reclassification from non-current to current portion based on maturity of the financial liabilities. As of December 31, 2015 New borrowings Repayments Liabilities assumed in connection with business combinations Other (1) Currency translation adjustment As of December 31, 2016 (in thousands) Borrowings $ 5,973 $ 5,846 $ (13,854 ) $ 7,067 $ 808 $ (316 ) $ 5,524 Financial liabilities relating to finance leases 23 — (27 ) — — 4 — Other financial liabilities 608 64 (286 ) 318 (225 ) (2 ) 477 Financial derivatives 552 — — — 1,505 (89 ) 1,968 Current portion 7,156 5,910 (14,167 ) 7,385 2,088 (403 ) 7,969 Borrowings 3,272 78,752 — — (808 ) (3,819 ) 77,397 Other financial liabilities — — — — 225 (11 ) 214 Non current portion 3,272 78,752 — — (583 ) (3,830 ) 77,611 Borrowings 9,245 84,598 (13,854 ) 7,067 — (4,135 ) 82,921 Financial liabilities relating to finance leases 23 — (27 ) — — 4 — Other financial liabilities 608 64 (286 ) 318 — (13 ) 691 Financial derivatives 552 — — — 1,505 (89 ) 1,968 Total $ 10,428 $ 84,662 $ (14,167 ) $ 7,385 $ 1,505 $ (4,233 ) $ 85,580 (1) Includes reclassification from non-current to current portion based on maturity of the financial liabilities.
Schedule of Debt	Our loans and RCF agreements are presented in the table below: Nominal/ Authorized amounts Amount drawn as of December 31, 2016 (RCF only) Nature (in thousands) Interest rate Settlement date Central loan agreements BPI Loan February 20, 2014 € 3,000 N/A Fixed: 2.09% May 31, 2021 Central RCF BPI RCF February 20, 2014 € 2,000 € 50 Floating rate: EURIBOR 3M + 0.7% 0.39% as of December 31, 2016 February 28, 2017 Bank Syndicate RCF September 24, 2015 € 250,000 $ 75,000 Floating rate: EURIBOR / LIBOR + margin depending on leverage ratio 1.73% as of December 31, 2016 September 23, 2020 China RCF HSBC RCF May 12, 2015 RMB 40,000 RMB 30,000 Floating rate: + 10% 4.79% as of December 31, 2016 N/A
Schedule of Maturities of Long-term Debt	The following table shows the maturity of our financial liabilities: Maturity Carrying value 2017 2018 2019 2020 2021 2022 (in thousands) Borrowings $ 82,921 $ 5,522 $ 817 $ 632 $ 75,634 $ 316 $ — Financial liabilities relating to finance leases — — — — — — — Other financial liabilities 691 477 — 214 — — — Bank overdraft — — — — — — — Financial derivatives 1,968 1,968 — — — — — Financial liabilities 85,580 7,967 817 846 75,634 316 —

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2016
Postemployment Benefits [Abstract]
Schedule Projected Benefit Obligations	The following table summarizes the changes in the projected benefit obligation: Year Ended December 31, 2014 2015 2016 (in thousands) Projected benefit obligation present value—beginning of period $ 1,276 $ 1,245 $ 1,445 Service cost 492 441 524 Interest cost 33 22 37 Actuarial losses (gains) (512 ) (128 ) 1,335 Change in consolidation scope 119 — 19 Currency translation adjustment (163 ) (135 ) (139 ) Projected benefit obligation present value—end of period $ 1,245 $ 1,445 $ 3,221
Schedule of Changes in Projected Benefit Obligations	The reconciliation of the changes in the present value of projected benefit obligation with the Consolidated Statements of Income for the presented periods is illustrated in the following table: Year Ended December 31, 2014 2015 2016 (in thousands) Service cost $ (492 ) $ (441 ) $ (524 ) Research and development expenses (167 ) (163 ) (211 ) Sales and operations expenses (188 ) (153 ) (144 ) General and administrative expenses (137 ) (125 ) (169 ) Interest cost (33 ) (22 ) (37 ) Financial income (expense) (33 ) (22 ) (37 ) Actuarial gains (losses) 512 128 (1,335 ) Accumulated other comprehensive income 512 128 (1,335 ) Amortization of net loss (gain) 12 — —
Schedule of Assumptions Used	The main assumptions used for the purposes of the actuarial valuations are listed below: Year Ended December 31, 2014 2015 2016 Discount rate (Corp AA) 1.5% 2.5% 1.9% Expected rate of salary increase 5.0% 5.0% 5.0% Expected rate of social charges 44.0% - 47.6% 48.0% - 51.0% 49.0% - 51.0% Expected staff turnover 0 - 15% 0 - 15% 0 - 10.5% Estimated retirement age 65 years old 65 years old Progressive table Life table INSEE - 2007 - 2009 TGHF 2005 TH-TF 2000-2002 shifted
Defined Contribution Plan Disclosures	Year Ended December 31, 2014 2015 2016 (in thousands) Defined contributions plans included in personnel expenses $ (6,522 ) $ (8,320 ) $ (11,061 )

Common Shares (Tables)

Common Shares (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Schedule of Change in Number of Shares	Change in Number of Shares Number of ordinary shares Balance at January 1, 2015 60,902,695 Issuance of shares under share option and free share plans (1) 1,568,186 Balance at December 31, 2015 62,470,881 Issuance of shares under share option and free share plans (2) 1,507,323 Balance at December 31, 2016 63,978,204 (1) Adopted by the Board of Directors on January 29, 2015, March 19, 2015, April 30, 2015, July 30, 2015, October 29, 2015 and December 17, 2015. (2) Adopted by the Board of Directors on January 29, 2016, February 25, 2016, April 20, 2016, June 28, 2016, July 28, 2016, October 27, 2016 and November 9, 2016.

Nature of Expenses Allocated 49

Nature of Expenses Allocated by Function (Tables)	12 Months Ended
	Dec. 31, 2016
Other Income and Expenses [Abstract]
Schedule of Nature of Expenses Allocated by Function	Nature of Expenses Allocated to Cost of Revenue Year Ended December 31, 2014 2015 2016 (in thousands) Traffic acquisition costs $ (585,492 ) $ (789,152 ) $ (1,068,911 ) Other cost of revenue (47,948 ) (62,201 ) (85,260 ) Hosting costs (24,780 ) (30,428 ) (41,978 ) Depreciation and amortization (21,455 ) (29,866 ) (38,469 ) Data acquisition (600 ) (257 ) (122 ) Other cost of sales (1,113 ) (1,650 ) (4,691 ) Total cost of revenue $ (633,440 ) $ (851,353 ) $ (1,154,171 ) Nature of Expenses Allocated to Research and Development Year Ended December 31, 2014 2015 2016 (in thousands) Personnel expenses $ (40,075 ) $ (58,075 ) $ (86,389 ) Personnel expense excluding equity awards compensation expense and research tax credit (41,456 ) (54,941 ) (79,222 ) Equity awards compensation expense (3,682 ) (6,520 ) (12,108 ) Research tax credit 5,063 3,386 4,941 Other cash operating expenses (14,888 ) (21,081 ) (29,867 ) Subcontracting and other headcount related costs (8,218 ) (12,592 ) (14,713 ) Rent and facilities costs (5,765 ) (7,107 ) (10,939 ) Consulting and professional fees (765 ) (1,201 ) (2,423 ) Marketing costs (97 ) (161 ) (953 ) Other (43 ) (20 ) (839 ) Other non-cash operating expenses (5,112 ) (7,651 ) (7,393 ) Depreciation and amortization (4,949 ) (7,995 ) (7,211 ) Net change in other provisions (163 ) 344 (182 ) Total research and development expenses $ (60,075 ) $ (86,807 ) $ (123,649 ) Nature of Expenses Allocated to Sales and Operations Year Ended December 31, 2014 2015 2016 (in thousands) Personnel expenses $ (119,609 ) $ (150,426 ) $ (185,065 ) Personnel expense excluding equity awards compensation expense (107,319 ) (138,748 ) (168,227 ) Equity awards compensation expense (12,290 ) (11,678 ) (16,838 ) Other cash operating expenses (52,077 ) (71,034 ) (84,127 ) Subcontracting and other headcount related costs (17,363 ) (20,856 ) (22,460 ) Rent and facilities costs (15,684 ) (25,542 ) (29,968 ) Marketing costs (9,443 ) (12,478 ) (15,225 ) Other (9,587 ) (12,158 ) (16,474 ) Other non-cash operating expenses (5,241 ) (8,070 ) (13,661 ) Depreciation and amortization (3,664 ) (5,178 ) (7,757 ) Net change in provisions for doubtful receivables (1,342 ) (2,660 ) (5,433 ) Net change in other provisions (235 ) (232 ) (471 ) Total sales and operations expenses $ (176,927 ) $ (229,530 ) $ (282,853 ) Nature of Expenses Allocated to General and Administrative Year Ended December 31, 2014 2015 2016 (in thousands) Personnel expenses $ (29,734 ) $ (37,670 ) $ (60,899 ) Personnel expense excluding equity awards compensation expense (26,106 ) (31,879 ) (46,586 ) Equity awards compensation expense (3,628 ) (5,791 ) (14,313 ) Other cash operating expenses (33,430 ) (41,814 ) (52,867 ) Subcontracting and other headcount related costs (17,452 ) (19,963 ) (22,990 ) Rent and facilities costs (4,731 ) (6,475 ) (9,516 ) Consulting and professional fees (10,094 ) (12,921 ) (18,298 ) Other (1,153 ) (2,455 ) (2,063 ) Other non-cash operating expenses (1,559 ) 339 (3,703 ) Depreciation and amortization (1,145 ) (1,526 ) (3,342 ) Net change in other provisions (414 ) (353 ) (361 ) Other — 2,218 — Total general and administrative expenses $ (64,723 ) $ (79,145 ) $ (117,469 )

Allocation of Personnel Expen50

Allocation of Personnel Expenses (Tables)	12 Months Ended
	Dec. 31, 2016
Compensation Related Costs [Abstract]
Schedule of Allocation of Personnel Expenses by Nature	Allocation of Personnel Expenses By Function Year Ended December 31, 2014 2015 2016 (in thousands) Research and development expenses $ (40,075 ) $ (58,075 ) $ (86,389 ) Sales and operations expenses (119,609 ) (150,426 ) (185,065 ) General and administrative expenses (29,734 ) (37,670 ) (60,899 ) Total personnel expenses $ (189,418 ) $ (246,171 ) $ (332,353 ) Allocation of Personnel Expenses by Nature Year Ended December 31, 2014 2015 2016 (in thousands) Wages and salaries $ (128,737 ) $ (170,079 ) $ (220,317 ) Severance pay (2,469 ) (1,343 ) (2,726 ) Social charges (38,814 ) (47,176 ) (59,668 ) Other social expenses (3,178 ) (6,033 ) (9,913 ) Acquisition-related deferred price consideration (950 ) (324 ) (85 ) Share based compensation (19,600 ) (23,989 ) (43,259 ) Profit sharing (733 ) (613 ) (1,326 ) Research tax credit (classified as a reduction of R&D expenses) 5,063 3,386 4,941 Total personnel expenses $ (189,418 ) $ (246,171 ) $ (332,353 )

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of share-based compensation by share-based payment award	Details of BSPCE / OSA / RSU plans Plans 1 & 2 Plan 3 Plan 4 Plan 5 Plan 6 Plan 6 Plan 7 Plan 8 Plan 9 Dates of grant (Boards of Directors) Oct 24, 2008 - Sept 14, 2010 Sept 9, 2009 - Sept 21, 2011 April 23, 2010 Nov 18, 2011 - May 22, 2012 Oct 25, 2012 Oct 25, 2012 - Sept 3, 2013 - April 23, 2014 July 30, 2014 - June 28, 2016 July 28, 2016 - Nov 9, 2016 Vesting period 3 years 3 - 4 years None 4 years 1 year 4-5 years 4 years 4 years 4 years 4 years 4 years Contractual life 10 years 10 years 10 years 10 years 10 years 10 years 10 years 10 years — 10 years — Expected option life 8 years 8 years 8 years 8 years 8 years 8 years 6 - 8 years 6 years — 6 years — Number of instruments granted 1,819,120 4,289,940 361,118 1,184,747 257,688 1,065,520 2,317,374 4,318,551 2,534,262 147,400 1,153,383 Type : Share Option (S.O.) / BSPCE / RSU BSPCE BSCPCE & OSA BSPCE BSCPCE & OSA BSPCE BSCPCE & OSA BSCPCE & OSA OSA RSU OSA RSU Share entitlement per option 1 1 1 1 1 1 1 1 1 1 1 Exercise price € 0.45 - € 0.20 - € 2.10 € 5.95 € 8.28 € 8.28 - € 12.08 - € 22.95 - — € 38.20 — Valuation method Black & Scholes Grant date share fair value € 0.20 - € 0.20 - € 2.10 € 4.98 € 6.43 € 5.45 - € 12.08 - € 22.50 - € 35.18 - € 38.20 € 33.98 - Expected volatility (1) 53.0% - 55.7% 55.2% - 57.8% 55.2% 52.1% - 52.9% 50.2% 49.6% - 50.2% 44.2% - 50.1% 39.4% - 44.5% — — — Discount rate (2) 2.74% - 4.10% 2.62% - 3.76% 3.4% 2.79% - 3.53% 2.2% 1.80% - 2.27% 1.20% - 2.40% 0.00% - 0.71% — — — Performance conditions No Yes (A) No No Yes (B) No No No Yes (C) No Yes (D) Fair value per option / RSU € 0.08 - € 0.08 - € 1.33 € 2.75 - € 3.28 € 3.28 - € 6.85 - € 9.47 - € 26.16 - € 14.49 € 33.98 - (1) Based on similar listed entities. (2) Based on Obligation Assimilables du Trésor, i.e. French government bonds with a ten -year maturity (“TEC 10 OAT floating-rate bonds”). (A) Options subject to performance condition: Among the 960,000 share options granted in April 7, 2011, 180,000 are subjected to performance conditions based on revenue excluding traffic acquisition costs targets that were met in 2012. (B) On October 25, 2012, the Board of Directors of the Parent also granted a total of 257,688 BSPCE to our co-founders. The conditions of exercise of these BSPCE are linked to a future liquidity event or a transfer of control of the Company, and the number of BSPCE that can be exercised are determined by the event’s date which cannot occur after March 31, 2014. Based on the assumptions known as at December 31, 2012, we determined that the share-based compensation expense would be recognized over a one -year period. This assumption was confirmed in 2013. (C) On October 29, 2015, the Board of Directors of the Parent also granted a total of 337,960 RSU to Criteo employees under condition of presence and to certain senior managers, employees and members of the management, subject to the achievement of internal performance objectives and condition of presence. Based on the assumptions known at December 31, 2015, we determined the share-based compensation expense by applying a probability ratio on performance objectives completion. This assumption was confirmed in 2016. On January 29, 2016, the Board of Directors of the Parent granted a total of 33,010 RSUs to members of the management, subject to the achievement of internal performance objectives and condition of presence. Based on the assumptions known at December 31, 2016, we determined the share-based compensation expense by applying a probability ratio on performance objectives completion. (D) On July 28, 2016, the Board of Directors of the Parent granted a total of 195,250 RSUs to certain senior managers and members of the management, subject to the achievement of internal performance objectives and condition of presence. Based on the assumptions known at December 31, 2016, we determined the share-based compensation expense by applying a probability ratio on performance objectives completion. Plan A Plan B Plan C Plan D Plan E Plan F Dates of grant Nov 17, 2009 March 11, 2010 Nov 16, 2010 - Sept 21, 2011 Oct 25, 2012 - March 6, 2013 March 19, 2015 - Oct 29, 2015 April 20, 2016 - Oct 27, 2016 Vesting period 2 years 3 years 2 years 2 years 1 - 4 years 1 - 4 years Contractual life 10 years 10 years 10 years 10 years 10 years 10 years Number of warrants granted 231,792 277,200 192,000 125,784 38,070 48,655 Share entitlement per warrant 1 1 1 1 1 1 Share warrant price €0.02 €0.07 - €0.11 €0.04 - €0.30 €0.43 - €0.48 €9.98 - €16.82 €13.89 - €14.55 Exercise price €0.70 €0.70 €0.70 - €5.95 €8.28 - €9.65 €35.18 - €41.02 €33.98 - €35.41 Valuation method used Black & Scholes Grant date share fair value €0.20 €0.70 €0.70 - €4.98 €6.43 - €9.65 €35.18 - €41.02 €33.98 - €35.41 Expected volatility (1) 55.7 % 55.2 % 53.5% - 55.0% 50.0% - 50.2% 39.9 % 40.6 % Discount rate (2) 3.58 % 3.44 % 2.62% - 3.38% 2.13% - 2.27% 0.% - 0.52% 0.10% - 0.25% Performance conditions No Yes (A) No No No No Fair value per warrant €0.05 €0.33 - €0.38 €0.40 - €2.58 €2.85 - €4.98 €9.98 - €16.82 €13.89 - €14.55 (1) Based on similar listed entities. (2) Based on Obligations Assimilables du Trésor, i.e. French government bonds with a ten-year maturity (“TEC 10 OAT floating-rate bonds”). (A) All the performance conditions were achieved during the period ended December 31, 2010. Breakdown of the Closing Balance Non-employee warrants Balance at December 31, 2014 Number outstanding 199,408 Weighted-average exercise price € 7.54 Number exercisable 155,609 Weighted-average exercise price € 6.88 Weighted-average remaining contractual life 7.5 years Balance at December 31, 2015 Number outstanding 154,910 Weighted-average exercise price € 15.72 Number exercisable 117,783 Weighted-average exercise price € 8.49 Weighted-average remaining contractual life 7.4 years Balance at December 31, 2016 Number outstanding 188,125 Weighted-average exercise price € 19.04 Number exercisable 117,096 Weighted-average exercise price € 11.73 Weighted-average remaining contractual life 7.3 years Change in Number of BSPCE / OSA / RSU Plans 1 & 2 Plan 3 Plan 4 Plan 5 Plan 6 Plan 7 Plan 8 Plan 9 RSUs Total Balance at January 1, 2014 1,134,737 2,333,763 361,118 1,929,299 1,204,248 1,555,144 — — — 8,518,309 Granted — — — — — 749,330 2,267,774 — — 3,017,104 Exercised (930,660 ) (1,315,733 ) (273,559 ) (337,352 ) (271,520 ) (47,019 ) — — — (3,175,843 ) Forfeited — (82,439 ) — (407,222 ) (42,928 ) (440,320 ) (30,820 ) — — (1,003,729 ) Balance at December 31, 2014 204,077 935,591 87,559 1,184,725 889,800 1,817,135 2,236,954 — — 7,355,841 Granted — — — — — — 1,621,734 — 1,103,405 2,725,139 Exercised (116,520 ) (449,069 ) (87,559 ) (343,021 ) (156,801 ) (310,827 ) (69,819 ) — — (1,533,616 ) Forfeited — (148,864 ) — (22,357 ) (40,068 ) (218,730 ) (466,086 ) — (7,820 ) (903,925 ) Balance at December 31, 2015 87,557 337,658 — 819,347 692,931 1,287,578 3,322,783 — 1,095,585 7,643,439 Granted — — — — — — 429,043 147,400 2,584,240 3,160,683 Exercised (33,403 ) (162,265 ) — (310,236 ) (281,166 ) (383,127 ) (300,126 ) — — (1,470,323 ) Forfeited — 300 — 3,956 (12,324 ) (153,923 ) (508,866 ) (23,025 ) (436,546 ) (1,130,428 ) Balance at December 31, 2016 54,154 175,693 — 513,067 399,441 750,528 2,942,834 124,375 3,243,279 8,203,371 Breakdown of the Closing Balance Plans 1 & 2 Plan 3 Plan 4 Plan 5 Plan 6 Plan 7 Plan 8 Plan 9 RSUs Total Balance at December 31, 2014 Number outstanding 204,077 935,591 87,559 1,184,725 889,800 1,817,135 2,236,954 — — 7,355,841 Weighted-average exercise price € 1.08 € 2.08 € 2.10 € 5.95 € 9.81 € 18.29 € 23.40 € — € — € 14.10 Number exercisable 204,077 883,399 87,559 730,371 362,778 394,785 — — — 2,662,969 Weighted-average exercise price € 1.08 € 1.94 € 2.10 € 5.95 € 9.58 € 14.02 € — € — € — € 5.81 Weighted-average remaining contractual life 4.6 years 5.8 years 5.3 years 7.3 years 8.1 years 8.9 years 9.6 years — — 8.2 years Balance at December 31, 2015 Number outstanding 87,557 337,658 — 819,347 692,931 1,287,578 3,322,783 — 1,095,585 7,643,439 Weighted-average exercise price € 1.41 € 3.14 € — € 5.95 € 9.75 € 17.97 € 30.50 € — € — € 20.97 Number exercisable 87,557 337,658 — 713,165 420,228 564,034 521,578 — — 2,644,220 Weighted-average exercise price € 1.41 € 3.14 € — € 5.95 € 9.58 € 17.24 € 23.32 € — € — € 11.85 Weighted-average remaining contractual life 3.6 years 4.8 years — 6.3 years 7.1 years 7.9 years 8.9 years — — 7.9 years Balance at December 31, 2016 Number outstanding 54,154 175,693 — 513,067 399,441 750,528 2,942,834 124,375 3,243,279 8,203,371 Weighted-average exercise price € 1.24 € 3.29 € — € 5.95 € 9.77 € 18.13 € 31.32 € 38.20 € — € 23.92 Number exercisable 54,154 175,693 — 513,067 325,596 504,262 1,135,634 — — 2,708,406 Weighted-average exercise price € 1.24 € 3.29 € — € 5.95 € 9.66 € 17.94 € 28.96 € — € — € 17.73 Weighted-average remaining contractual life 2.9 years 4.3 years — 5.2 years 6.1 years 6.8 years 8.2 years 9.6 years — 6.9 years Changes in Number of Non-Employee Warrants Balance at January 1, 2014 542,148 Granted 5,040 Exercised (345,780 ) Forfeited (2,000 ) Balance at December 31, 2014 199,408 Granted 38,070 Exercised (34,568 ) Forfeited (48,000 ) Balance at December 31, 2015 154,910 Granted 48,655 Exercised (37,000 ) Forfeited 21,560 Balance at December 31, 2016 188,125
Schedule of share-based compensation reconciliation with the Consolidated Statements of Income	Reconciliation with the Consolidated Statements of Income Balance for the year ended December 31, 2014 Balance for the year ended December 31, 2015 Balance for the year ended December 31, 2016 (in thousands) R&D S&O G&A Total R&D S&O G&A Total R&D S&O G&A Total RSUs — — — — (706 ) (1,046 ) (544 ) (2,296 ) (9,178 ) (12,705 ) (7,287 ) (29,170 ) Share options / BSPCE (3,682 ) (12,290 ) (3,497 ) (19,469 ) (5,814 ) (10,632 ) (5,001 ) (21,447 ) (2,930 ) (4,133 ) (5,356 ) (12,419 ) Plan 3 34 15 (36 ) 13 1 (6 ) — (5 ) — — — — Plan 5 (215 ) (134 ) (257 ) (606 ) (71 ) 27 (108 ) (152 ) (8 ) (27 ) (7 ) (42 ) Plan 6 (505 ) (1,358 ) (44 ) (1,907 ) (188 ) (384 ) (13 ) (585 ) (35 ) (20 ) (162 ) (217 ) Plan 7 (1,598 ) (8,494 ) (1,134 ) (11,226 ) (884 ) (1,758 ) (379 ) (3,021 ) (234 ) 239 (194 ) (189 ) Plan 8 (1,398 ) (2,319 ) (2,026 ) (5,743 ) (4,672 ) (8,511 ) (4,501 ) (17,684 ) (2,587 ) (4,258 ) (4,638 ) (11,483 ) Plan 9 — — — — — — — — (66 ) (67 ) (355 ) (488 ) Total share-based compensation (3,682 ) (12,290 ) (3,497 ) (19,469 ) (6,520 ) (11,678 ) (5,545 ) (23,743 ) (12,108 ) (16,838 ) (12,643 ) (41,589 ) BSAs — — (131 ) (131 ) — — (246 ) (246 ) — — (1,670 ) (1,670 ) Total equity awards compensation expense $ (3,682 ) $ (12,290 ) $ (3,628 ) $ (19,600 ) $ (6,520 ) $ (11,678 ) $ (5,791 ) $ (23,989 ) $ (12,108 ) $ (16,838 ) $ (14,313 ) $ (43,259 )

Financial Income and Expenses (

Financial Income and Expenses (Tables)	12 Months Ended
	Dec. 31, 2016
Other Income and Expenses [Abstract]
Schedule of Financial income (expense)	The Consolidated Statements of Income line item “Financial income (expense)” can be broken down as follows: Year Ended December 31, 2014 2015 2016 (in thousands) Financial income from cash equivalents $ 1,910 $ 2,105 $ 1,352 Interest and fees (583 ) (653 ) (2,367 ) Interest on debt (583 ) (553 ) (1,134 ) Fees — (100 ) (1,233 ) Foreign exchange (loss) gain 10,096 (5,971 ) 506 Other financial expense (33 ) (22 ) (37 ) Total financial income (expense) $ 11,390 $ (4,541 ) $ (546 )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Taxes	The Consolidated Statements of Income line item “Provision for income taxes” can be broken down as follows: Year Ended December 31, 2014 2015 2016 (in thousands) Current income tax $ (22,893 ) $ (25,265 ) $ (43,153 ) France (11,087 ) (15,458 ) (20,204 ) International (11,806 ) (9,807 ) (22,949 ) Net change in deferred taxes 5,315 15,748 10,024 France 671 2,009 2,654 International 4,644 13,739 7,370 Provision for income tax $ (17,578 ) $ (9,517 ) $ (33,129 )
Schedule of Effective Income Tax Rate Reconciliation	The following table shows the reconciliation between the effective and nominal tax expense at the nominal standard French rate of 34.43% (excluding additional contributions): Year Ended December 31, 2014 2015 2016 (in thousands) Income before taxes $ 64,474 $ 71,793 $ 120,458 Theoretical group tax-rates 34.43 % 34.43 % 34.43 % Nominal tax expense (22,198 ) (24,718 ) (41,474 ) Increase / decrease in tax expense arising from: Research tax credit 1,743 1,352 1,701 Net effect of shared based compensation (1) 3,419 2,048 (8,957 ) Other permanent differences (2,245 ) (804 ) (3,518 ) Non recognition of deferred tax assets related to tax losses and temporary differences (2) (3,546 ) (7,662 ) (7,738 ) Utilization or recognition of previously unrecognized tax losses (3) 276 12,264 13,366 French CVAE included in income taxes (2,467 ) (3,052 ) (3,165 ) Special tax deductions (4) 8,984 12,545 20,022 Effect of different tax rates (1,019 ) (1,046 ) (1,108 ) Other differences (525 ) (444 ) (2,258 ) Effective tax expense $ (17,578 ) $ (9,517 ) $ (33,129 ) Effective tax rate 27.3 % 13.3 % 27.5 % Increases and decreases in tax expense are presented applying the theoretical Group tax rate to the concerned tax bases. The impact resulting from the differences between local tax rates and the Group theoretical rate is shown in the “effect of different tax rates.” (1) While in most countries share-based compensation does not give rise to any tax effect either when granted or when exercised, the United States and the United Kingdom generally permit tax deductions in respect of share-based compensation. The tax deduction generated in the United States and United Kingdom is in connection with the significant number of options exercised during the period was offset by the share-based compensation accounting expense exclusion. (2) Deferred tax assets on which a valuation allowance has been recognized mainly relate to Criteo Ltd, Criteo do Brasil, Criteo Singapore Pte. Ltd and Criteo Advertising (Beijing) Co. Ltd tax losses. (3) The 2014 balance relates exclusively to Criteo Pty. The 2015 and 2016 balances mainly relate to the recognition of Criteo Corp. tax losses considering the projected taxable income within the next 3 years and the Section IRC 382 annual limitation. (4) Special tax deductions refer to the application of a reduced income tax rate on the majority of the technology royalties income invoiced by the Parent to its subsidiaries.
Schedule of Deferred Tax Assets and Liabilities	The following table shows the changes in the major sources of deferred tax assets and liabilities: (in thousands) Year ended December 31, 2014 Change recognized in profit or loss Change recognized in OCI Change in consolidation scope Other Currency translation adjustments Year ended December 31, 2015 Deferred tax assets: Net operating loss carryforwards $ 23,468 $ (385 ) $ — $ 5,889 $ — $ (549 ) $ 28,423 Personnel-related accruals 2,538 5,414 — 9 — (659 ) 7,302 Other accruals 2,285 1,353 — — — (545 ) 3,093 Projected benefit obligation 472 202 (44 ) — — (52 ) 578 Other 1,458 4,372 — 1,091 — (79 ) 6,842 Deferred tax assets (gross) 30,221 10,956 (44 ) 6,989 — (1,884 ) 46,238 Valuation allowance (19,863 ) 1,429 21 (7,177 ) — 1,610 (23,980 ) Deferred tax asset (net) 10,358 12,385 (23 ) (188 ) — (274 ) 22,258 Deferred tax liabilities: Intangible assets (2,861 ) 5,445 — (2,979 ) — 245 (150 ) Other (4 ) (2,082 ) — 47 — (12 ) (2,051 ) Deferred tax liabilities (2,865 ) 3,363 — (2,932 ) — 233 (2,201 ) Net deferred income tax balance $ 7,493 $ 15,748 $ (23 ) $ (3,120 ) $ — $ (41 ) $ 20,057 (in thousands) Year ended December 31, 2015 Change recognized in profit or loss Change recognized in OCI Change in consolidation scope Other Currency translation adjustments Year ended December 31, 2016 Deferred tax assets: Net operating loss carryforwards $ 28,423 $ (1,048 ) $ — $ — $ — $ (912 ) $ 26,463 Personnel-related accruals 7,302 257 — (30 ) 241 7,770 Other accruals 3,093 975 — 30 276 4,374 Projected benefit obligation 578 213 466 — — (50 ) 1,207 Other 6,842 7,331 — — (482 ) (265 ) 13,426 Deferred tax assets (gross) 46,238 7,728 466 — (482 ) (710 ) 53,240 Valuation allowance (23,980 ) 3,630 (16 ) — — 545 (19,821 ) Deferred tax asset (net) 22,258 11,358 450 — (482 ) (165 ) 33,419 Deferred tax liabilities: Intangible assets (150 ) (6 ) (477 ) — (33 ) 35 (631 ) Other (2,051 ) (1,328 ) — — 515 20 (2,844 ) Total deferred tax liabilities (2,201 ) (1,334 ) (477 ) — 482 55 (3,475 ) Net deferred income tax balance $ 20,057 $ 10,024 $ (27 ) $ — $ — $ (110 ) $ 29,944

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Schedule of basic and diluted earnings per share	Year Ended December 31, 2014 2015 2016 (in thousands, except share data) Net income attributable to shareholders of Criteo S.A. $ 45,556 $ 59,553 $ 82,272 Weighted average number of shares outstanding 58,928,563 61,835,499 63,337,792 Basic earnings per share $ 0.77 $ 0.96 $ 1.30 Year Ended December 31, 2014 2015 2016 (in thousands, except share data) Net income attributable to shareholders of Criteo S.A. $ 45,556 $ 59,553 $ 82,272 Weighted average number of shares outstanding of Criteo S.A. 58,928,563 61,835,499 63,337,792 Dilutive effect of : Restricted share awards — — 253,728 Share options and BSPCE 4,347,236 3,133,549 1,958,728 Share warrants 217,461 127,438 83,222 Weighted average number of shares outstanding used to determine diluted earnings per share 63,493,260 65,096,486 65,633,470 Diluted earnings per share $ 0.72 $ 0.91 $ 1.25
Schedule of weighted average number of anti-dilutive securities	The weighted average number of securities that were anti-dilutive for diluted EPS for the periods presented but which could potentially dilute EPS in the future are as follows: Year Ended December 31, 2014 2015 2016 Restricted share awards — 273,896 396,086 Share options and BSPCE 1,288,977 968,734 509,442 Share warrants — 15,925 — Weighted average number of anti-dilutive securities excluded from diluted earnings per share 1,288,977 1,258,555 905,528

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future payment obligations under non-cancellable operating leases as of December 31, 2016 are listed below: Less than 1 year 1 to 5 years 5 years + Total (in thousands) Minimum payments for property leases $ 33,655 $ 98,938 $ 49,551 $ 182,144 Minimum payments for hosting services 50,959 48,927 — 99,886 Minimum payments for other leases $ 4,197 $ 4,912 $ — $ 9,109

Related Parties (Tables)

Related Parties (Tables)	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	Total compensation for the Executive Officers, including social contributions, is summarized in the following table: Year Ended December 31, 2014 2015 2016 (in thousands) Short-term benefits (1) $ (4,145 ) $ (3,067 ) $ (2,755 ) Long-term benefits (2) (241 ) (245 ) (194 ) Shared-based compensation (3,291 ) (4,594 ) (7,159 ) Total $ (7,677 ) $ (7,906 ) $ (10,108 ) (1) wages, bonuses and other compensations (2) pension defined benefit plan

Breakdown of Revenue and Non-57

Breakdown of Revenue and Non-Current Assets by Geographical Areas (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Schedule of consolidated revenue for each geographical area	The following tables disclose our consolidated revenue for each geographical area for each of the reported periods. Revenue by geographical area is based on the location of advertisers’ campaigns. Americas EMEA Asia-Pacific Total (in thousands) December 31, 2014 $ 303,436 $ 485,986 $ 198,827 $ 988,249 December 31, 2015 505,653 541,105 276,411 1,323,169 December 31, 2016 $ 730,873 $ 660,523 $ 407,750 $ 1,799,146
Schedule of revenue generated in other significant countries	Revenue generated in other significant countries where we operate is presented in the following table: Year Ended December 31, 2014 2015 2016 (in thousands) Americas United States $ 237,385 $ 419,742 $ 630,047 EMEA Germany 105,544 111,792 137,116 United Kingdom 90,315 107,071 115,053 Asia-Pacific Japan $ 154,798 $ 190,066 $ 285,959
Schedule of non-current assets by geographical area and country	For each reported period, non-current assets (corresponding to the net book value of tangible and intangible assets) are presented in the table below. The geographical information results from the locations of legal entities. Of which Of which Holding Americas United States EMEA Asia-Pacific Japan Total (in thousands) December 31, 2015 $ 48,160 $ 24,437 $ 23,332 $ 8,847 $ 17,508 $ 7,807 $ 98,952 December 31, 2016 $ 55,052 $ 43,308 $ 42,474 $ 7,132 $ 26,033 $ 8,965 $ 131,525

Principles and Accounting Met58

Principles and Accounting Methods - Schedule of Consolidated Entities (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Criteo S.A
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo France SAS
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Finance SAS
Schedule of Investments [Line Items]
Voting rights	100.00%
Ownership Interest	100.00%
Criteo Ltd
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Corp
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Gmbh
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo KK
Schedule of Investments [Line Items]
Voting rights	66.00%	66.00%
Ownership Interest	66.00%	66.00%
Criteo Do Brasil LTDA
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo BV
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Pty
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Srl
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Advertising (Beijng) Co. Ltd
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Singapore Pte. Ltd.
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo LLC
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Europa S.L.
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Espana S.L.
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Canada Corp.
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo Reklamcılık Hizmetleri ve Ticaret Anonim Şirketi
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo MEA FZ-LLC
Schedule of Investments [Line Items]
Voting rights	100.00%	100.00%
Ownership Interest	100.00%	100.00%
Criteo India Private Ltd.
Schedule of Investments [Line Items]
Voting rights	100.00%
Ownership Interest	100.00%
HookLogic, Inc.
Schedule of Investments [Line Items]
Voting rights	100.00%
Ownership Interest	100.00%
HookLogic Ltd
Schedule of Investments [Line Items]
Voting rights	100.00%
Ownership Interest	100.00%
Hooklogic Brasil Solucoes EM Tecnología Ltda
Schedule of Investments [Line Items]
Voting rights	100.00%
Ownership Interest	100.00%

Principles and Accounting Met59

Principles and Accounting Methods - Additional Information (Details)	Nov. 09, 2016	Dec. 31, 2016
Minimum
Property, Plant and Equipment [Line Items]
Intangible asset, useful life (in years)		1 year
Ratio of value of instrument to hedged item		0.8
Maximum
Property, Plant and Equipment [Line Items]
Intangible asset, useful life (in years)		5 years
Ratio of value of instrument to hedged item		1.25
Fixtures and Fittings | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)		5 years
Fixtures and Fittings | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)		10 years
Furniture and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)		1 year
Furniture and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life (in years)		5 years
Software | Minimum
Property, Plant and Equipment [Line Items]
Weighted average useful life (in years)	1 year
Intangible asset, useful life (in years)		3 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Weighted average useful life (in years)	3 years
Intangible asset, useful life (in years)		5 years

Significant Events and Transa60

Significant Events and Transactions of the Period (Details)	12 Months Ended
	Dec. 31, 2016CNY (¥)	Dec. 31, 2016EUR (€)	Dec. 31, 2016USD ($)	Dec. 31, 2015CNY (¥)	Dec. 31, 2015USD ($)	Sep. 30, 2015EUR (€)	Sep. 30, 2015USD ($)	May 31, 2015CNY (¥)	May 31, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 31, 2014CNY (¥)
Business Acquisition [Line Items]
Amount drawn			$ 82,921,000		$ 9,245,000					$ 13,051,000
Criteo India Private Ltd.
Business Acquisition [Line Items]
Percentage of subsidiary held and controlled by Company	100.00%
Criteo Finance SAS
Business Acquisition [Line Items]
Percentage of subsidiary held and controlled by Company	100.00%
Revolving Credit Facility | Line of Credit | Bank Syndicate RCF
Business Acquisition [Line Items]
Amount drawn		€ 75,000,000	75,000,000
Maximum borrowing capacity		€ 250,000,000	263,500,000			€ 250,000,000	$ 263,500,000
Revolving Credit Facility | Line of Credit | HSBC Revolving Loan Facility
Business Acquisition [Line Items]
Amount drawn	¥ 30,000,000		4,300,000	¥ 25,000,000	$ 3,900,000
Maximum borrowing capacity	¥ 40,000,000		$ 5,800,000					¥ 40,000,000	$ 5,800,000		¥ 15,000,000

Business Combination - Addition

Business Combination - Additional Information (Details) $ in Thousands, € in Millions	Nov. 09, 2016USD ($)	May 31, 2016EUR (€)	May 31, 2016USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2016EUR (€)	Dec. 31, 2016USD ($)	May 31, 2016USD ($)
Business Acquisition [Line Items]
Amount drawn					$ 9,245	$ 13,051		$ 82,921
Goodwill					41,973	27,856		209,418
Acquisition costs				$ 85	324	950
Expected annual amortization of intangible assets				8,418	10,235
Payments to acquire businesses, net of cash acquired				235,541	$ 20,542	$ 26,103
HookLogic, Inc.
Business Acquisition [Line Items]
Consideration transferred	$ 250,100
Payments to acquire businesses, gross	175,100
Goodwill	165,300
Acquisition costs	2,200
Revenue of acquiree since acquisition date, actual				45,200
Revenue ex-TAC of acquiree since acquisition date, actual				12,300
Net income of acquiree since acquisition date, actual				2,700
Pro forma revenue				116,700
Pro forma revenue ex-TAC				34,100
Pro forma net income (loss)				$ (4,800)
HookLogic, Inc. | Technology Asset | Pro Forma
Business Acquisition [Line Items]
Expected annual amortization of intangible assets	6,000
HookLogic, Inc. | Customer Relationships | Pro Forma
Business Acquisition [Line Items]
Expected annual amortization of intangible assets	$ 8,600
HookLogic, Inc. | Weighted Average | Technology Asset
Business Acquisition [Line Items]
Weighted average useful life (in years)	4 years
HookLogic, Inc. | Weighted Average | Customer Relationships
Business Acquisition [Line Items]
Weighted average useful life (in years)	7 years
Monsieur Drive S.A.S.
Business Acquisition [Line Items]
Goodwill		€ 3.5							$ 3,700
Acquisition costs		0.2	$ 200
Payments to acquire businesses, net of cash acquired		4.6	$ 5,100
Deferred tax liability		0.2							200
Monsieur Drive S.A.S. | Technology Asset
Business Acquisition [Line Items]
Finite-lived asset acquired		€ 1.2							$ 1,200
Revolving Credit Facility | Bank Syndicate RCF | Line of Credit
Business Acquisition [Line Items]
Amount drawn							€ 75	$ 75,000
Revolving Credit Facility | Bank Syndicate RCF | Line of Credit | HookLogic, Inc.
Business Acquisition [Line Items]
Amount drawn	$ 75,000

Business Combination - Assets A

Business Combination - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Nov. 09, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 209,418		$ 41,973	$ 27,856
HookLogic, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents		$ 19,700
Trade receivables, net of allowances		29,200
Other current assets		1,000
Property, plant and equipment, net		1,300
Identifiable intangible assets		84,400
Non-current financial assets		300
Trade payables		(38,700)
Financial liabilities - current portion		(7,400)
Other taxes		(500)
Employee-related payables		(1,400)
Other current liabilities		(3,100)
Total identifiable net assets		84,800
Goodwill		165,300
Total fair value of consideration transferred		$ 250,100

Business Combination - Acquired

Business Combination - Acquired Intangible Assets (Details) - HookLogic, Inc.	Nov. 09, 2016USD ($)
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 84,400
Technology Asset
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	24,400
Customer Relationships
Business Acquisition [Line Items]
Finite-lived Intangible Assets Acquired	$ 60,000
Minimum | Technology Asset
Business Acquisition [Line Items]
Total identifiable intangible assets acquired	3 years
Minimum | Customer Relationships
Business Acquisition [Line Items]
Total identifiable intangible assets acquired	5 years
Maximum | Technology Asset
Business Acquisition [Line Items]
Total identifiable intangible assets acquired	5 years
Maximum | Customer Relationships
Business Acquisition [Line Items]
Total identifiable intangible assets acquired	9 years

Categories of Financial Asset64

Categories of Financial Assets and Financial Liabilities - Financial Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 756,872	$ 677,884
Carrying Value | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	270,317	353,537
Carrying Value | Trade receivables, net of allowances
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	397,244	261,581
Carrying Value | Other taxes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	52,942	29,552
Carrying Value | Other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	19,340	16,030
Carrying Value | Financial assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	17,029	17,184
Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	756,872	677,884
Fair value | Loans and receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	486,555	324,347
Fair value | Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	270,317	353,537
Fair value | Trade receivables, net of allowances
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	397,244	261,581
Fair value | Trade receivables, net of allowances | Loans and receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	397,244	261,581
Fair value | Other taxes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	52,942	29,552
Fair value | Other taxes | Loans and receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	52,942	29,552
Fair value | Other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	19,340	16,030
Fair value | Other current assets | Loans and receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	19,340	16,030
Fair value | Financial assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	17,029	17,184
Fair value | Financial assets | Loans and receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 17,029	$ 17,184

Categories of Financial Asset65

Categories of Financial Assets and Financial Liabilities - Credit Risks (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Allowance for doubtful accounts receivable, period increase (decrease)	$ 5,400	$ 2,300
Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, maximum exposure	756,872	677,884
Cash and cash equivalents | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	270,317	353,537
Trade receivables, net of allowances | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	397,244	261,581
Other taxes | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	52,942	29,552
Other current assets | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	19,340	16,030
Financial assets | Carrying Value
Concentration Risk [Line Items]
Concentration risk, maximum exposure	$ 17,029	$ 17,184

Categories of Financial Asset66

Categories of Financial Assets and Financial Liabilities - Trade Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Gross value	$ 408,842	$ 267,845
Allowance	(11,598)	(6,264)
Not Yet Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Gross value	265,600	193,603
Allowance	0	0
Accounts Receivable, 1 to 30 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Gross value	92,163	53,803
Allowance	(49)	0
Accounts Receivable, 31 to 60 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Gross value	19,747	8,287
Allowance	(182)	0
Accounts Receivable, 61 to 90 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Gross value	6,055	2,574
Allowance	(191)	(2)
Accounts Receivable, Greater than 90 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Gross value	25,277	9,578
Allowance	$ (11,176)	$ (6,262)
Accounts Receivable
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	100.00%	100.00%
Accounts Receivable | Not Yet Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	65.00%	72.20%
Accounts Receivable | Accounts Receivable, 1 to 30 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	22.50%	20.10%
Accounts Receivable | Accounts Receivable, 31 to 60 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	4.80%	3.10%
Accounts Receivable | Accounts Receivable, 61 to 90 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	1.50%	1.00%
Accounts Receivable | Accounts Receivable, Greater than 90 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	6.20%	3.60%
Allowance for Doubtful Accounts
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	100.00%	100.00%
Allowance for Doubtful Accounts | Not Yet Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	0.00%	0.00%
Allowance for Doubtful Accounts | Accounts Receivable, 1 to 30 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	0.40%	0.00%
Allowance for Doubtful Accounts | Accounts Receivable, 31 to 60 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	1.60%	0.00%
Allowance for Doubtful Accounts | Accounts Receivable, 61 to 90 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	1.60%	0.00%
Allowance for Doubtful Accounts | Accounts Receivable, Greater than 90 Days Past Due
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Concentration risk, percentage	96.40%	100.00%

Categories of Financial Asset67

Categories of Financial Assets and Financial Liabilities - Financial Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
of which derivative financial instruments	$ 1,968	$ 552	$ 743
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trade payables	365,788	246,382
Other taxes	44,831	30,463
Employee - related payables	55,874	42,275
Other current liabilities	30,221	15,531
Financial liabilities	85,580	10,428
of which derivative financial instruments	1,968	553
Total liabilities, Fair value	582,294	345,079
Fair value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trade payables	365,788	246,382
Other taxes	44,831	30,463
Employee - related payables	55,874	42,275
Other current liabilities	30,221	15,531
Financial liabilities	85,580	10,428
of which derivative financial instruments	1,968	553
Total liabilities, Fair value	$ 582,294	$ 345,079

Cash and Cash Equivalents - Bre

Cash and Cash Equivalents - Breakdown of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and Cash Equivalents [Abstract]
Money market funds	$ 31,688	$ 54,188
Interest-bearing bank deposits	88,091	114,127
Cash and cash equivalents	150,538	185,222
Total Cash and cash equivalents	$ 270,317	$ 353,537	$ 351,827	$ 323,181

Cash and Cash Equivalents - All

Cash and Cash Equivalents - Allocation by Currency of Financial Liabilities and Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and Cash Equivalents [Line Items]
Borrowings	$ 82,921	$ 9,245	$ 13,051
Other financial liabilities	691	608	679
Financial derivatives	1,968	552	743
Financial liabilities	85,580	10,428	14,780
Cash and cash equivalents	270,317	$ 353,537	$ 351,827	$ 323,181
EUR
Cash and Cash Equivalents [Line Items]
Borrowings	3,289
Other financial liabilities	450
Financial derivatives	1,968
Financial liabilities	5,707
Cash and cash equivalents	197,997
GBP
Cash and Cash Equivalents [Line Items]
Borrowings	0
Other financial liabilities	0
Financial derivatives	0
Financial liabilities	0
Cash and cash equivalents	2,887
USD
Cash and Cash Equivalents [Line Items]
Borrowings	75,253
Other financial liabilities	241
Financial derivatives	0
Financial liabilities	75,494
Cash and cash equivalents	29,636
CNY
Cash and Cash Equivalents [Line Items]
Borrowings	4,379
Other financial liabilities	0
Financial derivatives	0
Financial liabilities	4,379
Cash and cash equivalents	3,074
JPY
Cash and Cash Equivalents [Line Items]
Borrowings	0
Other financial liabilities	0
Financial derivatives	0
Financial liabilities	0
Cash and cash equivalents	17,316
KRW
Cash and Cash Equivalents [Line Items]
Borrowings	0
Other financial liabilities	0
Financial derivatives	0
Financial liabilities	0
Cash and cash equivalents	2,531
Other
Cash and Cash Equivalents [Line Items]
Borrowings	0
Other financial liabilities	0
Financial derivatives	0
Financial liabilities	0
Cash and cash equivalents	$ 16,876

Trade Receivables - Net Book Va

Trade Receivables - Net Book Value (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Trade accounts receivables	$ 408,842	$ 267,845
(Less) Allowance for doubtful accounts	(11,598)	(6,264)	$ (3,930)	$ (2,529)
Net book value at end of period	$ 397,244	$ 261,581

Trade Receivables - Allowance f

Trade Receivables - Allowance for Doubtful Accounts Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ (6,264)	$ (3,930)	$ (2,529)
Provision for doubtful accounts	(9,898)	(2,660)	(2,248)
Reversal of provision	4,464	0	910
Change in consolidation scope	(221)	(99)	(450)
Currency translation adjustment	321	425	387
Balance at end of period	$ (11,598)	$ (6,264)	$ (3,930)

Other Current Assets (Details)

Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepayments to suppliers	$ 2,439	$ 2,774
Employee-related receivables	97	94
Taxes receivables	52,942	29,552
Other debtors	3,166	3,687
Prepaid expenses	13,638	9,475
Gross book value at end of period	72,282	45,582
Net book value at end of period	$ 72,282	$ 45,582

Property, Plant, and Equipmen73

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	$ 82,482	$ 52,239
Additions to tangible assets	76,030	68,247
Disposal of tangible assets	(8)	(101)
Depreciation expense	(48,161)	(34,327)
Change in consolidation scope	490	118
Currency translation adjustment	(2,252)	(3,694)
Transfer into service	0	0
Ending Balance	108,581	82,482
Gross book value at end of period	215,892	146,522
Accumulated depreciation and impairment at end of period	(107,311)	(64,040)
Fixtures and Fittings
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	14,343	2,501
Additions to tangible assets	6,188	13,408
Disposal of tangible assets	0	(53)
Depreciation expense	(4,496)	(1,840)
Change in consolidation scope	85	31
Currency translation adjustment	(499)	(488)
Transfer into service	2,544	784
Ending Balance	18,165	14,343
Gross book value at end of period	24,200	15,948
Accumulated depreciation and impairment at end of period	(6,035)	(1,605)
Furniture and Equipment
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	63,533	47,391
Additions to tangible assets	57,866	50,849
Disposal of tangible assets	(8)	(48)
Depreciation expense	(43,665)	(32,487)
Change in consolidation scope	405	87
Currency translation adjustment	(1,665)	(2,936)
Transfer into service	1,283	677
Ending Balance	77,749	63,533
Gross book value at end of period	179,025	125,968
Accumulated depreciation and impairment at end of period	(101,276)	(62,435)
Construction in Progress
Movement in Property, Plant and Equipment [Roll Forward]
Beginning Balance	4,606	2,347
Additions to tangible assets	11,976	3,990
Disposal of tangible assets	0	0
Depreciation expense	0	0
Change in consolidation scope	0	0
Currency translation adjustment	(88)	(270)
Transfer into service	(3,827)	(1,461)
Ending Balance	12,667	4,606
Gross book value at end of period	12,667	4,606
Accumulated depreciation and impairment at end of period	$ 0	$ 0

Intangible assets - Schedule of

Intangible assets - Schedule of Changes in Net Book Value of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 16,470	$ 12,821
Additions to intangible assets	8,525	7,371
Amortization expense	(8,418)	(10,235)
Change in consolidation scope	87,021	7,801
Currency translation adjustment	(654)	(1,288)
Transfer into service	0	0
Ending balance	102,944	16,470
Gross book value at end of period	129,992	35,550
Accumulated depreciation and impairment at end of period	(27,048)	(19,080)
Construction in Progress
Indefinite-lived Intangible Assets [Roll Forward]
Beginning balance	1,149	343
Additions to intangible assets	0	1,172
Change in consolidation scope	788	0
Currency translation adjustment	(14)	(52)
Transfer into service	(1,029)	(314)
Ending balance	894	1,149
Software
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	6,881	5,122
Additions to intangible assets	7,972	5,645
Amortization expense	(3,449)	(3,631)
Change in consolidation scope	3	1
Currency translation adjustment	(455)	(570)
Transfer into service	435	314
Ending balance	11,387	6,881
Gross book value at end of period	22,770	15,863
Accumulated depreciation and impairment at end of period	(11,383)	(8,982)
Technology and customer relationships
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	8,440	7,356
Additions to intangible assets	553	554
Amortization expense	(4,969)	(6,604)
Change in consolidation scope	86,230	7,800
Currency translation adjustment	(185)	(666)
Transfer into service	594	0
Ending balance	90,663	8,440
Gross book value at end of period	106,328	18,538
Accumulated depreciation and impairment at end of period	$ (15,665)	$ (10,098)

Intangible assets - Schedule 75

Intangible assets - Schedule of Expected Amortization Expense for Intangible assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Entities Excluding HookLogic
Finite-Lived Intangible Assets [Line Items]
2,017	$ 7,825
2,018	6,732
2,019	2,654
2,020	586
2,021	11
Total	17,808
Software
Finite-Lived Intangible Assets [Line Items]
Total	11,387	$ 6,881	$ 5,122
Software | Consolidated Entities Excluding HookLogic
Finite-Lived Intangible Assets [Line Items]
2,017	5,116
2,018	4,321
2,019	2,218
2,020	586
2,021	11
Total	12,252
Technology and customer relationships
Finite-Lived Intangible Assets [Line Items]
Total	90,663	$ 8,440	$ 7,356
Technology and customer relationships | Consolidated Entities Excluding HookLogic
Finite-Lived Intangible Assets [Line Items]
2,017	2,709
2,018	2,411
2,019	436
2,020	0
2,021	0
Total	$ 5,556
Software, Technology, and Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Average life (in years)	3 years

Non-Current Financial Assets (D

Non-Current Financial Assets (Details) $ in Millions	Dec. 31, 2016USD ($)
Interest-bearing Deposits
Guarantor Obligations [Line Items]
Deposit assets	$ 6.6

Goodwill - Schedule of Goodwill

Goodwill - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill
Goodwill	$ 41,973	$ 27,856
Additions to goodwill	169,197	16,695
Currency translation adjustment	(1,752)	(2,578)
Goodwill	$ 209,418	$ 41,973

Goodwill - Additional Informati

Goodwill - Additional Information (Details) $ in Thousands, € in Millions	Feb. 17, 2015USD ($)	Apr. 07, 2014EUR (€)	Apr. 07, 2014USD ($)	Feb. 19, 2014EUR (€)	Feb. 19, 2014USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013EUR (€)	Dec. 31, 2013USD ($)	Apr. 07, 2014USD ($)	Feb. 19, 2014USD ($)
Goodwill [Line Items]
Payments to acquire businesses, net of cash acquired						$ 235,541	$ 20,542	$ 26,103
Goodwill						209,418	41,973	27,856
Acquisition costs						$ 85	$ 324	$ 950
DataPop, Inc.
Goodwill [Line Items]
Consideration transferred	$ 22,000
Cash acquired from acquisition	3,700
Payments to acquire businesses, net of cash acquired	18,300
Goodwill	16,700
Acquisition costs	600
DataPop, Inc. | Technology Asset
Goodwill [Line Items]
Finite-lived asset acquired	$ 7,800
AdQuantic
Goodwill [Line Items]
Payments to acquire businesses, net of cash acquired		€ 3	$ 4,100
Goodwill		2.8									$ 3,900
Acquisition costs		€ 0.1	$ 100
Tedemis
Goodwill [Line Items]
Consideration transferred				€ 21	$ 29,000
Payments to acquire businesses, gross				17	23,400
Deferred tax assets				2.3								$ 3,200
Goodwill				15.6								21,600
Acquisition costs				0.4	500				€ 0.1	$ 100
Contingent consideration				€ 4	$ 5,500
Milestone period (in years)				2 years	2 years
Tedemis | Technology Asset
Goodwill [Line Items]
Finite-lived asset acquired				€ 2.8								3,900
Tedemis | Cookie Pool
Goodwill [Line Items]
Finite-lived asset acquired				€ 4.6								$ 6,300

Contingencies (Details)

Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Loss Contingency Accrual [Roll Forward]
Contingencies accrual, beginning balance	$ 668	$ 1,373
Charges	837	632
Provision used	(450)	(487)
Provision released not used	(391)	(727)
Currency translation adjustments	(10)	(123)
Contingencies accrual, ending balance	654	668
Contingencies accrual, of which current	654
Provision for employee- related litigation
Loss Contingency Accrual [Roll Forward]
Contingencies accrual, beginning balance	236	781
Charges	671	200
Provision used	(402)	(487)
Provision released not used	0	(186)
Currency translation adjustments	(20)	(72)
Contingencies accrual, ending balance	485	236
Contingencies accrual, of which current	485
Provision for tax- related litigation
Loss Contingency Accrual [Roll Forward]
Contingencies accrual, beginning balance	44	592
Charges	0	44
Provision used	0	0
Provision released not used	(44)	(541)
Currency translation adjustments	0	(51)
Contingencies accrual, ending balance	0	44
Contingencies accrual, of which current	0
Other provisions
Loss Contingency Accrual [Roll Forward]
Contingencies accrual, beginning balance	388	0
Charges	166	388
Provision used	(48)	0
Provision released not used	(347)	0
Currency translation adjustments	10	0
Contingencies accrual, ending balance	169	$ 388
Contingencies accrual, of which current	$ 169

Other Current Liabilities (Deta

Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Clients' prepayments	$ 9,176	$ 6,244
Employee-related payables	55,874	42,275
Other taxes	44,831	30,463
Accounts payable relating to capital expenditures	15,484	8,037
Other creditors	2,440	1,091
Deferred revenue	3,121	159
Total	$ 130,926	$ 88,269

Financial Liabilities - Changes

Financial Liabilities - Changes in Current and Noncurrent Financial Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Financial Liabilities Activity [Roll Forward]
Borrowings, current portion, beginning balance	$ 5,973	$ 8,007
Financial liabilities relating to finance leases, current portion, beginning balance	23	282
Other financial liabilities, current portion, beginning balance	608	488
Derivative instruments, current portion, beginning balance	552	743
Financial liabilities, current portion, beginning balance	7,156	9,520
Borrowings, non current portion, beginning balance	3,272	5,044
Financial liabilities relating to finance leases, non current portion, beginning balance	0	25
Other financial liabilities, non current portion, beginning balance	0	191
Financial liabilities, non current portion, beginning balance	3,272	5,260
Borrowings, beginning balance	9,245	13,051
Financial liabilities relating to finance leases, beginning balance	23	307
Other financial liabilities, beginning balance	608	679
Derivative instruments, beginning balance	552	743
Financial liabilities, beginning balance	10,428	14,780
New borrowings	84,662	4,023
Repayments of financial liabilities	(14,167)	(9,974)
Liabilities assumed in connection with business combinations	7,385	2,796
Other	1,505	208
Currency translation adjustment	(4,233)	(1,405)
Borrowings, current portion, ending balance	5,524	5,973
Financial liabilities relating to finance leases, current portion, ending balance	0	23
Other financial liabilities, current portion, ending balance	477	608
Derivative instruments, current portion, ending balance	1,968	552
Financial liabilities, current portion, ending balance	7,969	7,156
Borrowings, non current portion, ending balance	77,397	3,272
Financial liabilities relating to finance leases, non current portion, ending balance		0
Other financial liabilities, non current portion, ending balance	214	0
Financial liabilities, non current portion, ending balance	77,611	3,272
Borrowings, ending balance	82,921	9,245
Financial liabilities relating to finance leases, ending balance	0	23
Other financial liabilities, ending balance	691	608
Derivative instruments, ending balance	1,968	552
Financial liabilities, ending balance	85,580	10,428
Borrowings
Financial Liabilities Activity [Roll Forward]
New borrowings	84,598	4,023
Repayments of borrowings	(13,854)	(8,716)
Liabilities assumed in connection with business combinations	7,067	1,796
Other	0	324
Currency translation adjustment	(4,135)	(1,233)
Financial liabilities relating to finance leases
Financial Liabilities Activity [Roll Forward]
Repayments of financial liabilities relating to finance leases	(27)	(258)
Liabilities assumed in connection with business combinations	0	0
Other	0	0
Currency translation adjustment	4	(26)
Other financial liabilities
Financial Liabilities Activity [Roll Forward]
New borrowings	64	0
Repayments of other financial liabilities	(286)	(1,000)
Liabilities assumed in connection with business combinations	318	1,000
Other	0	0
Currency translation adjustment	(13)	(71)
Financial derivatives
Financial Liabilities Activity [Roll Forward]
Liabilities assumed in connection with business combinations	0	0
Other	1,505	(116)
Currency translation adjustment	(89)	(75)
Financial liabilities, Current portion
Financial Liabilities Activity [Roll Forward]
New borrowings	5,910	4,023
Repayments of financial liabilities	(14,167)	(9,974)
Liabilities assumed in connection with business combinations	7,385	2,796
Other	2,088	1,681
Currency translation adjustment	(403)	(890)
Financial liabilities, Current portion | Borrowings
Financial Liabilities Activity [Roll Forward]
New borrowings	5,846	4,023
Repayments of borrowings	(13,854)	(8,716)
Liabilities assumed in connection with business combinations	7,067	1,796
Other	808	1,599
Currency translation adjustment	(316)	(736)
Financial liabilities, Current portion | Financial liabilities relating to finance leases
Financial Liabilities Activity [Roll Forward]
Repayments of financial liabilities relating to finance leases	(27)	(258)
Liabilities assumed in connection with business combinations	0	0
Other	0	24
Currency translation adjustment	4	(25)
Financial liabilities, Current portion | Other financial liabilities
Financial Liabilities Activity [Roll Forward]
New borrowings	64	0
Repayments of other financial liabilities	(286)	(1,000)
Liabilities assumed in connection with business combinations	318	1,000
Other	(225)	174
Currency translation adjustment	(2)	(54)
Financial liabilities, Current portion | Financial derivatives
Financial Liabilities Activity [Roll Forward]
Liabilities assumed in connection with business combinations	0	0
Other	1,505	(116)
Currency translation adjustment	(89)	(75)
Financial liablities, Non current portion
Financial Liabilities Activity [Roll Forward]
New borrowings	78,752	0
Repayments of financial liabilities	0	0
Liabilities assumed in connection with business combinations	0	0
Other	(583)	(1,473)
Currency translation adjustment	(3,830)	(515)
Financial liablities, Non current portion | Borrowings
Financial Liabilities Activity [Roll Forward]
New borrowings	78,752	0
Repayments of borrowings	0	0
Liabilities assumed in connection with business combinations	0	0
Other	(808)	(1,275)
Currency translation adjustment	(3,819)	(497)
Financial liablities, Non current portion | Financial liabilities relating to finance leases
Financial Liabilities Activity [Roll Forward]
Repayments of financial liabilities relating to finance leases		0
Liabilities assumed in connection with business combinations		0
Other		(24)
Currency translation adjustment		(1)
Financial liablities, Non current portion | Other financial liabilities
Financial Liabilities Activity [Roll Forward]
New borrowings	0	0
Repayments of other financial liabilities	0	0
Liabilities assumed in connection with business combinations	0	0
Other	225	(174)
Currency translation adjustment	$ (11)	$ (17)

Financial Liabilities - Loans a

Financial Liabilities - Loans and RCF Agreements (Details)	12 Months Ended
	Dec. 31, 2016CNY (¥)	Dec. 31, 2016EUR (€)	Dec. 31, 2016USD ($)	Dec. 31, 2015CNY (¥)	Dec. 31, 2015USD ($)	Sep. 30, 2015EUR (€)	Sep. 30, 2015USD ($)	May 31, 2015CNY (¥)	May 31, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 31, 2014CNY (¥)	Feb. 28, 2014EUR (€)	Feb. 28, 2014USD ($)
Debt Instrument [Line Items]
Amount drawn | $			$ 82,921,000		$ 9,245,000					$ 13,051,000
Loans Payable | 2.09% Bpifrance Financement (Fench Public Investment Bank) Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount		€ 3,000,000										€ 3,000,000	$ 3,200,000
Interest rate, stated percentage	2.09%	2.09%	2.09%
Line of Credit | Revolving Credit Facility | Bpifrance Financement (French Public Investment Bank) RCF
Debt Instrument [Line Items]
Maximum borrowing capacity | €		€ 2,000,000
Amount drawn		50,000	$ 100,000
Line of Credit | Revolving Credit Facility | Bank Syndicate RCF
Debt Instrument [Line Items]
Maximum borrowing capacity		250,000,000	263,500,000			€ 250,000,000	$ 263,500,000
Amount drawn		€ 75,000,000	75,000,000
Line of Credit | Revolving Credit Facility | HSBC Revolving Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	¥ 40,000,000		5,800,000					¥ 40,000,000	$ 5,800,000		¥ 15,000,000
Amount drawn	¥ 30,000,000		$ 4,300,000	¥ 25,000,000	$ 3,900,000
Line of Credit | Euribor 3 Months | Revolving Credit Facility | Bpifrance Financement (French Public Investment Bank) RCF
Debt Instrument [Line Items]
Basis spread on variable rate	0.70%
Interest rate at period end	0.39%	0.39%	0.39%
Line of Credit | EURIBOR / LIBOR | Revolving Credit Facility | Bank Syndicate RCF
Debt Instrument [Line Items]
Interest rate at period end	1.73%	1.73%	1.73%
Line of Credit | People’s Bank of China Rate Effective on Loan Drawdown Date | Revolving Credit Facility | HSBC Revolving Loan Facility
Debt Instrument [Line Items]
Basis spread on variable rate	10.00%
Interest rate at period end	4.79%	4.79%	4.79%

Financial Liabilities - Additio

Financial Liabilities - Additional Information (Details)

1 Months Ended

12 Months Ended

Sep. 30, 2015EUR (€)

May 31, 2015CNY (¥)

Feb. 28, 2014EUR (€)

Dec. 31, 2016CNY (¥)

Dec. 31, 2016EUR (€)

Dec. 31, 2016USD ($)

Dec. 31, 2015CNY (¥)

Dec. 31, 2015EUR (€)

Dec. 31, 2015USD ($)

Sep. 30, 2015USD ($)

May 31, 2015USD ($)

Dec. 31, 2014USD ($)

Oct. 31, 2014CNY (¥)

Feb. 28, 2014USD ($)

Debt Instrument [Line Items]

Amount drawn | $

$ 82,921,000

$ 9,245,000

$ 13,051,000

Line of Credit | Bank Syndicate RCF | Revolving Credit Facility

Debt Instrument [Line Items]

Maximum borrowing capacity

€ 250,000,000

€ 250,000,000

263,500,000

$ 263,500,000

Amount drawn

75,000,000

75,000,000

Line of Credit | Bpifrance Financement (French Public Investment Bank) RCF | Revolving Credit Facility

Debt Instrument [Line Items]

Maximum borrowing capacity

2,000,000

Amount drawn

50,000

100,000

Line of Credit | Bpifrance Financement (French Public Investment Bank) RCF | Revolving Credit Facility | Euribor 3 Months

Debt Instrument [Line Items]

Basis spread on variable rate

0.70%

Line of Credit | Central RCF | Revolving Credit Facility

Debt Instrument [Line Items]

Amount drawn

100,000

Line of Credit | HSBC Revolving Loan Facility | Revolving Credit Facility

Debt Instrument [Line Items]

Maximum borrowing capacity

¥ 40,000,000

¥ 40,000,000

5,800,000

$ 5,800,000

¥ 15,000,000

Amount drawn

¥ 30,000,000

$ 4,300,000

¥ 25,000,000

3,900,000

Line of Credit | HSBC Revolving Loan Facility | Revolving Credit Facility | People’s Bank of China Rate Effective on Loan Drawdown Date

Debt Instrument [Line Items]

Basis spread on variable rate

10.00%

Revolving Credit Facility | Bank Syndicate RCF

Debt Instrument [Line Items]

Debt instrument, term (in years)

5 years

Revolving Credit Facility | Bpifrance Financement (French Public Investment Bank) RCF

Debt Instrument [Line Items]

Debt instrument, term (in years)

3 years

Maximum borrowing capacity

€ 3,000,000

€ 1,000,000

$ 1,000,000

$ 3,200,000

Amount of decrease each subsequent year

€ 1,000,000

1,000,000

Commitment fee percentage

0.30%

Revolving Credit Facility | Bpifrance Financement (French Public Investment Bank) RCF | Euribor 3 Months

Debt Instrument [Line Items]

Basis spread on variable rate

0.70%

Revolving Credit Facility | HSBC Revolving Loan Facility | People’s Bank of China Rate Effective on Loan Drawdown Date

Debt Instrument [Line Items]

Basis spread on variable rate

10.00%

Loans Payable | 2.09% Bpifrance Financement (Fench Public Investment Bank) Term Loan

Debt Instrument [Line Items]

Debt instrument, term (in years)

7 years

Debt instrument, face amount

€ 3,000,000

€ 3,000,000

$ 3,200,000

Grace period (in years)

2 years

Financial Liabilities - Maturit

Financial Liabilities - Maturity of Financial Liabilities and Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Borrowings
Borrowings	$ 82,921	$ 9,245	$ 13,051
Next fiscal year	5,522
Year two	817
Year three	632
Year four	75,634
Year five	316
Year six	0
Financial liabilities relating to finance leases
Financial liabilities relating to finance leases	0	23	307
Next fiscal year	0
Year two	0
Year three	0
Year four	0
Year five	0
Year six	0
Other financial liabilities
Other financial liabilities	691	608	679
Next fiscal year	477
Year two	0
Year three	214
Year four	0
Year five	0
Year six	0
Bank overdraft
Bank overdrafts	0
Next fiscal year	0
Year two	0
Year three	0
Year four	0
Year five	0
Year six	0
Financial derivatives
Financial liabilities	1,968	552	743
Next fiscal year	1,968
Year two	0
Year three	0
Year four	0
Year five	0
Year six	0
Financial liabilities
Financial liabilities	85,580	$ 10,428	$ 14,780
Next fiscal year	7,967
Year two	817
Year three	846
Year four	75,634
Year five	316
Year six	$ 0

Employee Benefits - Schedule of

Employee Benefits - Schedule of Projected Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation present value—beginning of period	$ 3,221	$ 1,445	$ 1,245	$ 1,276
Service cost	524	441	492
Interest cost	37	22	33
Actuarial losses (gains)	1,335	(128)	(512)
Change in consolidation scope	19	0	119
Currency translation adjustment	(139)	(135)	(163)
Projected benefit obligation present value—end of period	$ 3,221	$ 1,445	$ 1,245

Employee Benefits - Schedule 86

Employee Benefits - Schedule of Reconciliation of Changes in Present Value of Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ (524)	$ (441)	$ (492)
Interest cost	(37)	(22)	(33)
Actuarial gains (losses)	(1,335)	128	512
Amortization of net loss (gain)	0	0	12
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial gains (losses)	(1,335)	128	512
Research and Development Expense
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	(211)	(163)	(167)
Sales And Operations Expense
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	(144)	(153)	(188)
General and Administrative Expense
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	(169)	(125)	(137)
Interest Income (Expense)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	$ (37)	$ (22)	$ (33)

Employee Benefits - Schedule 87

Employee Benefits - Schedule of Assumptions Used for Actuarial Valuations (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Discount rate (Corp AA)	1.90%	2.50%	1.50%
Expected rate of salary increase	5.00%	5.00%	5.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected rate of social charges	49.00%	48.00%	44.00%
Expected staff turnover	0.00%	0.00%	0.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected rate of social charges	51.00%	51.00%	47.60%
Expected staff turnover	10.50%	15.00%	15.00%

Employee Benefits - Schedule 88

Employee Benefits - Schedule of Defined Contribution Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined contributions plans included in personnel expenses	$ (11,061)	$ (8,320)	$ (6,522)

Common Shares (Details)

Common Shares (Details) € / shares in Units, € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016EUR (€)€ / sharesshares	Dec. 31, 2015€ / sharesshares	Dec. 31, 2016USD ($)
Equity [Abstract]
Common shares, par value (in Euro per share) | € / shares	€ 0.025	€ 0.025
Common shares outstanding, value	€ 1.6		$ 2.1
Common Stock, Shares Outstanding [Roll Forward]
Beginning balance (in shares)	62,470,881	60,902,695
Issuance of shares under share option and free share plans (in shares)	1,507,323	1,568,186
Ending balance (in shares)	63,978,204	62,470,881

Nature of Expenses Allocated 90

Nature of Expenses Allocated by Function - Cost of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Income and Expenses [Abstract]
Traffic acquisition costs	$ (1,068,911)	$ (789,152)	$ (585,492)
Other cost of revenue	(85,260)	(62,201)	(47,948)
Hosting costs	(41,978)	(30,428)	(24,780)
Depreciation and amortization	(38,469)	(29,866)	(21,455)
Data acquisition	(122)	(257)	(600)
Other cost of sales	(4,691)	(1,650)	(1,113)
Total cost of revenue	$ (1,154,171)	$ (851,353)	$ (633,440)

Nature of Expenses Allocated 91

Nature of Expenses Allocated by Function - Research and Development (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Personnel expenses	$ (332,353)	$ (246,171)	$ (189,418)
Personnel expense excluding equity awards compensation expense and research tax credit	(220,317)	(170,079)	(128,737)
Equity awards compensation expense	(43,259)	(23,989)	(19,600)
Research tax credit	4,941	3,386	5,063
Total research and development expenses	(123,649)	(86,807)	(60,075)
Research and Development Expense
Condensed Income Statements, Captions [Line Items]
Personnel expenses	(86,389)	(58,075)	(40,075)
Personnel expense excluding equity awards compensation expense and research tax credit	(79,222)	(54,941)	(41,456)
Equity awards compensation expense	(12,108)	(6,520)	(3,682)
Research tax credit	4,941	3,386	5,063
Other cash operating expenses	(29,867)	(21,081)	(14,888)
Subcontracting and other headcount related costs	(14,713)	(12,592)	(8,218)
Rent and facilities costs	(10,939)	(7,107)	(5,765)
Consulting and professional fees	(2,423)	(1,201)	(765)
Marketing costs	(953)	(161)	(97)
Other	(839)	(20)	(43)
Other non-cash operating expenses	(7,393)	(7,651)	(5,112)
Depreciation and amortization	(7,211)	(7,995)	(4,949)
Net change in other provisions	$ (182)	$ 344	$ (163)

Nature of Expenses Allocated 92

Nature of Expenses Allocated by Function - Sales and Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Personnel expenses	$ (332,353)	$ (246,171)	$ (189,418)
Personnel expense excluding equity awards compensation expense and research tax credit	(220,317)	(170,079)	(128,737)
Equity awards compensation expense	(43,259)	(23,989)	(19,600)
Provision for doubtful accounts	(9,898)	(2,660)	(2,248)
Total sales and operations expenses	(282,853)	(229,530)	(176,927)
Sales And Operations Expense
Condensed Income Statements, Captions [Line Items]
Personnel expenses	(185,065)	(150,426)	(119,609)
Personnel expense excluding equity awards compensation expense and research tax credit	(168,227)	(138,748)	(107,319)
Equity awards compensation expense	(16,838)	(11,678)	(12,290)
Other cash operating expenses	(84,127)	(71,034)	(52,077)
Subcontracting and other headcount related costs	(22,460)	(20,856)	(17,363)
Rent and facilities costs	(29,968)	(25,542)	(15,684)
Marketing costs	(15,225)	(12,478)	(9,443)
Other	(16,474)	(12,158)	(9,587)
Other non-cash operating expenses	(13,661)	(8,070)	(5,241)
Depreciation and amortization	(7,757)	(5,178)	(3,664)
Provision for doubtful accounts	(5,433)	(2,660)	(1,342)
Net change in other provisions	$ (471)	$ (232)	$ (235)

Nature of Expenses Allocated 93

Nature of Expenses Allocated by Function - General and Administrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Personnel expenses	$ (332,353)	$ (246,171)	$ (189,418)
Personnel expense excluding equity awards compensation expense and research tax credit	(220,317)	(170,079)	(128,737)
Equity awards compensation expense	(43,259)	(23,989)	(19,600)
Provision for doubtful accounts	(9,898)	(2,660)	(2,248)
Total general and administrative expenses	(117,469)	(79,145)	(64,723)
General and Administrative Expense
Condensed Income Statements, Captions [Line Items]
Personnel expenses	(60,899)	(37,670)	(29,734)
Personnel expense excluding equity awards compensation expense and research tax credit	(46,586)	(31,879)	(26,106)
Equity awards compensation expense	(14,313)	(5,791)	(3,628)
Other cash operating expenses	(52,867)	(41,814)	(33,430)
Subcontracting and other headcount related costs	(22,990)	(19,963)	(17,452)
Rent and facilities costs	(9,516)	(6,475)	(4,731)
Consulting and professional fees	(18,298)	(12,921)	(10,094)
Other	(2,063)	(2,455)	(1,153)
Other non-cash operating expenses	(3,703)	339	(1,559)
Depreciation and amortization	(3,342)	(1,526)	(1,145)
Provision for doubtful accounts	(361)	(353)	(414)
Other	$ 0	$ 2,218	$ 0

Allocation of Personnel Expen94

Allocation of Personnel Expenses - Allocation of Personnel Expenses by Function (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Income Statements, Captions [Line Items]
Personnel expenses	$ (332,353)	$ (246,171)	$ (189,418)
Research and Development Expense
Condensed Income Statements, Captions [Line Items]
Personnel expenses	(86,389)	(58,075)	(40,075)
Sales And Operations Expense
Condensed Income Statements, Captions [Line Items]
Personnel expenses	(185,065)	(150,426)	(119,609)
General and Administrative Expense
Condensed Income Statements, Captions [Line Items]
Personnel expenses	$ (60,899)	$ (37,670)	$ (29,734)

Allocation of Personnel Expen95

Allocation of Personnel Expenses - Allocation of Personnel Expenses by Nature (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation Related Costs [Abstract]
Wages and salaries	$ (220,317)	$ (170,079)	$ (128,737)
Severance pay	(2,726)	(1,343)	(2,469)
Social charges	(59,668)	(47,176)	(38,814)
Other social expenses	(9,913)	(6,033)	(3,178)
Acquisition-related deferred price consideration	(85)	(324)	(950)
Share based compensation	43,259	23,989	19,600
Profit sharing	(1,326)	(613)	(733)
Research tax credit	4,941	3,386	5,063
Personnel expenses	$ (332,353)	$ (246,171)	$ (189,418)

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - shares

Jun. 29, 2016

Jun. 18, 2014

Aug. 02, 2013

Sep. 14, 2012

Nov. 18, 2011

Apr. 07, 2011

Apr. 23, 2010

Sep. 09, 2009

Apr. 16, 2009

Oct. 24, 2008

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Average percent of closing share prices

95.00%

BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

48,655,000

38,070,000

5,040,000

RSUs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

RSUs granted (in shares)

2,584,240,000

1,103,405,000

0

Plan 1 | BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

2,112,000

Number of shares authorized to be granted (in shares)

2,112,000

Plan 2 | BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

1,472,800

Number of shares authorized to be granted (in shares)

1,472,800

Plan 3 | OSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

1,584,000

Number of shares authorized to be granted (in shares)

1,584,000

Options granted (in shares)

960,000

Plan 3 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares authorized to be granted (in shares)

2,700,000

Options granted (in shares)

0

0

0

Expiration period (in years)

10 years

Plan 4 | BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

361,118

Expiration period (in years)

10 years

Plan 4 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

0

0

0

Plan 5 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

2,800,000

Number of shares authorized to be granted (in shares)

2,800,000

Options granted (in shares)

0

0

0

Expiration period (in years)

10 years

Award vesting period (in years)

4 years

Plan 6 | BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expiration period (in years)

10 years

Award vesting period (in years)

1 year

Plan 6 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

1,654,290

Number of shares authorized to be granted (in shares)

1,654,290

Options granted (in shares)

0

0

0

Expiration period (in years)

10 years

Plan 7 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

6,627,237

Number of shares authorized to be granted (in shares)

6,627,237

Options granted (in shares)

0

0

749,330,000

Expiration period (in years)

10 years

Award vesting period (in years)

4 years

Plan 8 | OSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

9,935,710

Number of shares authorized to be granted (in shares)

9,935,710

Expiration period (in years)

10 years

Award vesting period (in years)

4 years

Plan 8 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

429,043,000

1,621,734,000

2,267,774,000

Plan 8 | RSUs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period (in years)

4 years

Plan 9

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expiration period (in years)

10 years

Plan 9 | OSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expiration period (in years)

10 years

Award vesting period (in years)

4 years

Plan 9 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

147,400,000

0

0

Plan 9 | OSAs and RSUs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

4,600,000

Plan 9 | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Additional shares authorized (in shares)

100,000

Number of shares authorized to be granted (in shares)

4,600,000

Plan 9 | RSUs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period (in years)

4 years

Plans 1, 2, and 3 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expiration period (in years)

10 years

Plan A | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

231,792,000

Expiration period (in years)

10 years

Award vesting period (in years)

2 years

Plan B | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

277,200,000

Expiration period (in years)

10 years

Award vesting period (in years)

3 years

Plan C | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

192,000,000

Expiration period (in years)

10 years

Award vesting period (in years)

2 years

Plan D, Advisory Board | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expiration period (in years)

10 years

Plan D | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

125,784,000

Expiration period (in years)

10 years

Award vesting period (in years)

2 years

Plan E and Plan F | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expiration period (in years)

10 years

Vesting Period 1 | RSUs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

50.00%

Vesting Period 1 | Plan 9 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

25.00%

Vesting Period 1 | Plans 1, 2, and 3 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

33.33%

Vesting Period 1 | Plan A | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

12.50%

Award vesting period (in years)

24 months

Vesting Period 1 | Plan B | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

33.33%

Vesting Period 1 | Plan C | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

4.17%

Award vesting period (in years)

24 months

Vesting Period 1 | Plan D, Advisory Board | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

4.17%

Award vesting period (in years)

24 months

Vesting Period 1 | Plan D, Non-advisory Board [Member] | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

33.33%

Vesting Period 1 | Plan E and Plan F | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

25.00%

Vesting Period 2 | RSUs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

6.25%

Award vesting period (in years)

24 months

Vesting Period 2 | Plan 9

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting period (in years)

36 months

Vesting Period 2 | Plan 9 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

6.25%

Vesting Period 2 | Plans 1, 2, and 3 | OSA and BSPCE

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

8.33%

Award vesting period (in years)

24 months

Vesting Period 2 | Plan B | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

8.33%

Award vesting period (in years)

24 months

Vesting Period 2 | Plan D, Non-advisory Board [Member] | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

33.33%

Vesting Period 2 | Plan E and Plan F | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

6.25%

Award vesting period (in years)

36 months

Vesting Period 3 | Plan D, Non-advisory Board [Member] | BSA

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Award vesting rights, percentage

33.33%

Share-Based Compensation - Deta

Share-Based Compensation - Details of BSPCE / OSA / RSU plans (Details) - € / shares	Jul. 28, 2016	Jan. 29, 2016	Oct. 29, 2015	Oct. 25, 2012	Apr. 07, 2011	Apr. 23, 2010	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted (in shares)							2,584,240,000	1,103,405,000	0
Plans 1 and 2 | BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							3 years
Contractual life (in years)							10 years
Expected option life (in years)							8 years
Number of instruments granted (in shares)							1,819,120
Share entitlement per option (in shares)							1
Plans 1 and 2 | BSPCE | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in Euro per share)							€ 0.45
Option, grant date share fair value (in Euro per share)							€ 0.20
Expected volatility rate							53.00%
Discount rate							2.74%
Fair value per award (in Euro per share)							€ 0.08
Plans 1 and 2 | BSPCE | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in Euro per share)							2.10
Option, grant date share fair value (in Euro per share)							€ 0.70
Expected volatility rate							55.70%
Discount rate							4.10%
Fair value per award (in Euro per share)							€ 0.45
Plans 1 and 2 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)							0	0	0
Plan 3 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)							10 years
Expected option life (in years)							8 years
Number of instruments granted (in shares)							4,289,940
Share entitlement per option (in shares)							1
Options granted (in shares)							0	0	0
Plan 3 | OSA and BSPCE | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							3 years
Exercise price (in Euro per share)							€ 0.20
Option, grant date share fair value (in Euro per share)							€ 0.20
Expected volatility rate							55.20%
Discount rate							2.62%
Fair value per award (in Euro per share)							€ 0.08
Plan 3 | OSA and BSPCE | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Exercise price (in Euro per share)							€ 5.95
Option, grant date share fair value (in Euro per share)							€ 4.98
Expected volatility rate							57.80%
Discount rate							3.76%
Fair value per award (in Euro per share)							€ 2.88
Plan 3 | OSA
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)					960,000
Plan 3 | Performance OSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)					180,000
Plan 4 | BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)							10 years
Expected option life (in years)							8 years
Number of instruments granted (in shares)							361,118
Exercise price (in Euro per share)							€ 2.10
Share entitlement per option (in shares)							1
Option, grant date share fair value (in Euro per share)							€ 2.10
Expected volatility rate							55.20%
Discount rate							3.40%
Fair value per award (in Euro per share)							€ 1.33
Options granted (in shares)						361,118
Plan 4 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)							0	0	0
Plan 5 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Contractual life (in years)							10 years
Expected option life (in years)							8 years
Number of instruments granted (in shares)							1,184,747
Exercise price (in Euro per share)							€ 5.95
Share entitlement per option (in shares)							1
Option, grant date share fair value (in Euro per share)							€ 4.98
Options granted (in shares)							0	0	0
Plan 5 | OSA and BSPCE | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate							52.10%
Discount rate							2.79%
Fair value per award (in Euro per share)							€ 2.75
Plan 5 | OSA and BSPCE | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate							52.90%
Discount rate							3.53%
Fair value per award (in Euro per share)							€ 2.85
Plan 6 | BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							1 year
Contractual life (in years)							10 years
Expected option life (in years)							8 years
Number of instruments granted (in shares)							257,688
Exercise price (in Euro per share)							€ 8.28
Share entitlement per option (in shares)							1
Option, grant date share fair value (in Euro per share)							€ 6.43
Expected volatility rate							50.20%
Discount rate							2.20%
Fair value per award (in Euro per share)							€ 3.28
Plan 6 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)							10 years
Expected option life (in years)							8 years
Number of instruments granted (in shares)							1,065,520
Share entitlement per option (in shares)							1
Options granted (in shares)							0	0	0
Plan 6 | OSA and BSPCE | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Exercise price (in Euro per share)							€ 8.28
Option, grant date share fair value (in Euro per share)							€ 5.45
Expected volatility rate							49.60%
Discount rate							1.80%
Fair value per award (in Euro per share)							€ 3.28
Plan 6 | OSA and BSPCE | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							5 years
Exercise price (in Euro per share)							€ 10.43
Option, grant date share fair value (in Euro per share)							€ 6.43
Expected volatility rate							50.20%
Discount rate							2.27%
Fair value per award (in Euro per share)							€ 5.83
Plan 6 | Performance BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)				257,688
Period for recognition (in years)										1 year
Plan 7 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Contractual life (in years)							10 years
Number of instruments granted (in shares)							2,317,374
Share entitlement per option (in shares)							1
Options granted (in shares)							0	0	749,330,000
Plan 7 | OSA and BSPCE | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option life (in years)							6 years
Exercise price (in Euro per share)							€ 12.08
Option, grant date share fair value (in Euro per share)							€ 12.08
Expected volatility rate							44.20%
Discount rate							1.20%
Fair value per award (in Euro per share)							€ 6.85
Plan 7 | OSA and BSPCE | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option life (in years)							8 years
Exercise price (in Euro per share)							€ 38.81
Option, grant date share fair value (in Euro per share)							€ 38.81
Expected volatility rate							50.10%
Discount rate							2.40%
Fair value per award (in Euro per share)							€ 16.90
Plan 8 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)							429,043,000	1,621,734,000	2,267,774,000
Plan 8 | OSA
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Contractual life (in years)							10 years
Expected option life (in years)							6 years
Number of instruments granted (in shares)							4,318,551
Share entitlement per option (in shares)							1
Plan 8 | OSA | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in Euro per share)							€ 22.95
Option, grant date share fair value (in Euro per share)							€ 22.50
Expected volatility rate							39.40%
Discount rate							0.00%
Fair value per award (in Euro per share)							€ 9.47
Plan 8 | OSA | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price (in Euro per share)							47.47
Option, grant date share fair value (in Euro per share)							€ 47.47
Expected volatility rate							44.50%
Discount rate							0.71%
Fair value per award (in Euro per share)							€ 17.97
Plan 8 | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Number of RSUs granted (in shares)							2,534,262
Share entitlement per option (in shares)							1
Plan 8 | RSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option, grant date share fair value (in Euro per share)							€ 35.18
Fair value per award (in Euro per share)							26.16
Plan 8 | RSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option, grant date share fair value (in Euro per share)							35.58
Fair value per award (in Euro per share)							€ 37.10
Plan 8 | Performance RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted (in shares)		33,010	337,960
Plan 9
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)							10 years
Plan 9 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)							147,400,000	0	0
Plan 9 | OSA
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Contractual life (in years)							10 years
Expected option life (in years)							6 years
Number of instruments granted (in shares)							147,400
Exercise price (in Euro per share)							€ 38.20
Share entitlement per option (in shares)							1
Option, grant date share fair value (in Euro per share)							€ 38.20
Fair value per award (in Euro per share)							€ 14.49
Plan 9 | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)							4 years
Number of RSUs granted (in shares)							1,153,383
Share entitlement per option (in shares)							1
Plan 9 | RSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option, grant date share fair value (in Euro per share)							€ 33.98
Fair value per award (in Euro per share)							33.98
Plan 9 | RSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option, grant date share fair value (in Euro per share)							39.03
Fair value per award (in Euro per share)							€ 39.03
Plan 9 | Performance RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted (in shares)	195,250

Share-Based Compensation - Chan

Share-Based Compensation - Change in Number of BSPCE/OSA/RSU (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised, options (in shares)	(1,470,323,000)	(1,533,616,000)	(3,175,843,000)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments [Roll Forward]
Beginning balance (in shares)	7,643,439,000	7,355,841,000	8,518,309,000
Granted (in shares)	3,160,683,000	2,725,139,000	3,017,104,000
Forfeited (in shares)	(1,130,428,000)	(903,925,000)	(1,003,729,000)
Ending balance (in shares)	8,203,371,000	7,643,439,000	7,355,841,000
OSA and BSPCE | Plans 1 and 2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	87,557,000	204,077,000	1,134,737,000
Options granted (in shares)	0	0	0
Exercised, options (in shares)	(33,403,000)	(116,520,000)	(930,660,000)
Forfeited, options (in shares)	0	0	0
Ending balance, options (in shares)	54,154,000	87,557,000	204,077,000
OSA and BSPCE | Plan 3
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	337,658,000	935,591,000	2,333,763,000
Options granted (in shares)	0	0	0
Exercised, options (in shares)	(162,265,000)	(449,069,000)	(1,315,733,000)
Forfeited, options (in shares)	300,000	(148,864,000)	(82,439,000)
Ending balance, options (in shares)	175,693,000	337,658,000	935,591,000
OSA and BSPCE | Plan 4
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	0	87,559,000	361,118,000
Options granted (in shares)	0	0	0
Exercised, options (in shares)	0	(87,559,000)	(273,559,000)
Forfeited, options (in shares)	0	0	0
Ending balance, options (in shares)	0	0	87,559,000
OSA and BSPCE | Plan 5
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	819,347,000	1,184,725,000	1,929,299,000
Options granted (in shares)	0	0	0
Exercised, options (in shares)	(310,236,000)	(343,021,000)	(337,352,000)
Forfeited, options (in shares)	3,956,000	(22,357,000)	(407,222,000)
Ending balance, options (in shares)	513,067,000	819,347,000	1,184,725,000
OSA and BSPCE | Plan 6
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	692,931,000	889,800,000	1,204,248,000
Options granted (in shares)	0	0	0
Exercised, options (in shares)	(281,166,000)	(156,801,000)	(271,520,000)
Forfeited, options (in shares)	(12,324,000)	(40,068,000)	(42,928,000)
Ending balance, options (in shares)	399,441,000	692,931,000	889,800,000
OSA and BSPCE | Plan 7
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	1,287,578,000	1,817,135,000	1,555,144,000
Options granted (in shares)	0	0	749,330,000
Exercised, options (in shares)	(383,127,000)	(310,827,000)	(47,019,000)
Forfeited, options (in shares)	(153,923,000)	(218,730,000)	(440,320,000)
Ending balance, options (in shares)	750,528,000	1,287,578,000	1,817,135,000
OSA and BSPCE | Plan 8
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	3,322,783,000	2,236,954,000	0
Options granted (in shares)	429,043,000	1,621,734,000	2,267,774,000
Exercised, options (in shares)	(300,126,000)	(69,819,000)	0
Forfeited, options (in shares)	(508,866,000)	(466,086,000)	(30,820,000)
Ending balance, options (in shares)	2,942,834,000	3,322,783,000	2,236,954,000
OSA and BSPCE | Plan 9
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, options (in shares)	0	0	0
Options granted (in shares)	147,400,000	0	0
Exercised, options (in shares)	0	0	0
Forfeited, options (in shares)	(23,025,000)	0	0
Ending balance, options (in shares)	124,375,000	0	0
RSU
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares)	1,095,585,000	0	0
RSUs granted (in shares)	2,584,240,000	1,103,405,000	0
Forfeited (in shares)	(436,546,000)	(7,820,000)	0
Ending balance (in shares)	3,243,279,000	1,095,585,000	0

Share-Based Compensation - Brea

Share-Based Compensation - Breakdown of the Closing Balance (Details)	12 Months Ended
	Dec. 31, 2016$ / sharesshares	Dec. 31, 2015$ / sharesshares	Dec. 31, 2014$ / sharesshares	Dec. 31, 2016€ / sharesshares	Dec. 31, 2015€ / sharesshares	Dec. 31, 2014€ / sharesshares	Dec. 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 23.92	€ 20.97	€ 14.10
Number exercisable (in shares)	2,708,406,000	2,644,220,000	2,662,969,000	2,708,406,000	2,644,220,000	2,662,969,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 17.73	€ 11.85	€ 5.81
Weighted-average remaining contractual life, options (in years)	6 years 10 months 24 days	7 years 10 months 24 days	8 years 2 months 12 days
Number outstanding, equity awards (in shares)	8,203,371,000	7,643,439,000	7,355,841,000	8,203,371,000	7,643,439,000	7,355,841,000	8,518,309,000
BSA
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	188,125,000	154,910,000	199,408,000	188,125,000	154,910,000	199,408,000	542,148,000
Outstanding, weighted-average exercise price, options (in Euro per share) | $ / shares	$ 19.04	$ 15.72	$ 7.54
Number of exercisable options (in shares)	117,096,000	117,783,000	155,609,000	117,096,000	117,783,000	155,609,000
Exercisable, weighted-average exercise price, options (in Euro per share) | $ / shares	$ 11.73	$ 8.49	$ 6.88
Weighted-average remaining contractual life, options (in years)	7 years 3 months 18 days	7 years 4 months 24 days	7 years 6 months
RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, RSUs (in shares)	3,243,279,000	1,095,585,000	0	3,243,279,000	1,095,585,000	0	0
Plans 1 and 2 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	54,154,000	87,557,000	204,077,000	54,154,000	87,557,000	204,077,000	1,134,737,000
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 1.24	€ 1.41	€ 1.08
Number exercisable (in shares)	54,154,000	87,557,000	204,077,000	54,154,000	87,557,000	204,077,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 1.24	€ 1.41	€ 1.08
Weighted-average remaining contractual life, options (in years)	2 years 10 months 24 days	3 years 7 months 6 days	4 years 7 months 6 days
Plan 3 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	175,693,000	337,658,000	935,591,000	175,693,000	337,658,000	935,591,000	2,333,763,000
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 3.29	€ 3.14	€ 2.08
Number exercisable (in shares)	175,693,000	337,658,000	883,399,000	175,693,000	337,658,000	883,399,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 3.29	€ 3.14	€ 1.94
Weighted-average remaining contractual life, options (in years)	4 years 3 months 18 days	4 years 9 months 18 days	5 years 9 months 18 days
Plan 4 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	0	0	87,559,000	0	0	87,559,000	361,118,000
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 0	€ 0	€ 2.10
Number exercisable (in shares)	0	0	87,559,000	0	0	87,559,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 0	€ 0	€ 2.10
Weighted-average remaining contractual life, options (in years)			5 years 3 months 18 days
Plan 5 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	513,067,000	819,347,000	1,184,725,000	513,067,000	819,347,000	1,184,725,000	1,929,299,000
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 5.95	€ 5.95	€ 5.95
Number exercisable (in shares)	513,067,000	713,165,000	730,371,000	513,067,000	713,165,000	730,371,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 5.95	€ 5.95	€ 5.95
Weighted-average remaining contractual life, options (in years)	5 years 2 months 12 days	6 years 3 months 18 days	7 years 3 months 18 days
Plan 6 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	399,441,000	692,931,000	889,800,000	399,441,000	692,931,000	889,800,000	1,204,248,000
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 9.77	€ 9.75	€ 9.81
Number exercisable (in shares)	325,596,000	420,228,000	362,778,000	325,596,000	420,228,000	362,778,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 9.66	€ 9.58	€ 9.58
Weighted-average remaining contractual life, options (in years)	6 years 1 month 6 days	7 years 1 month 6 days	8 years 1 month 6 days
Plan 7 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	750,528,000	1,287,578,000	1,817,135,000	750,528,000	1,287,578,000	1,817,135,000	1,555,144,000
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 18.13	€ 17.97	€ 18.29
Number exercisable (in shares)	504,262,000	564,034,000	394,785,000	504,262,000	564,034,000	394,785,000
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 17.94	€ 17.24	€ 14.02
Weighted-average remaining contractual life, options (in years)	6 years 9 months 18 days	7 years 10 months 24 days	8 years 10 months 24 days
Plan 8 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	2,942,834,000	3,322,783,000	2,236,954,000	2,942,834,000	3,322,783,000	2,236,954,000	0
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 31.32	€ 30.50	€ 23.40
Number exercisable (in shares)	1,135,634,000	521,578,000	0	1,135,634,000	521,578,000	0
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 28.96	€ 23.32	€ 0
Weighted-average remaining contractual life, options (in years)	8 years 2 months 12 days	8 years 10 months 24 days	9 years 7 months 6 days
Plan 9 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number outstanding, options (in shares)	124,375,000	0	0	124,375,000	0	0	0
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 38.20	€ 0	€ 0
Number exercisable (in shares)	0	0	0	0	0	0
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 0	€ 0	€ 0
Weighted-average remaining contractual life, options (in years)	9 years 7 months 6 days

Share-Based Compensation - D100

Share-Based Compensation - Details of Non-Employee Warrants (Details) - BSA - € / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of grants (in shares)	48,655,000	38,070,000	5,040,000
Plan A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	2 years
Contractual life (in years)	10 years
Number of grants (in shares)	231,792,000
Share entitlement per warrant (in shares)	1
Share warrant price (in Euro per share)	€ 0.02
Exercise price (in Euro per share)	0.70
Grant date share fair value (in Euro per share)	€ 0.20
Expected volatility rate	55.70%
Discount rate	3.58%
Fair value per warrant (in Euro per share)	€ 0.05
Plan B
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Contractual life (in years)	10 years
Number of grants (in shares)	277,200,000
Share entitlement per warrant (in shares)	1
Exercise price (in Euro per share)	€ 0.70
Grant date share fair value (in Euro per share)	€ 0.70
Expected volatility rate	55.20%
Discount rate	3.44%
Plan B | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share warrant price (in Euro per share)	€ 0.07
Fair value per warrant (in Euro per share)	0.33
Plan B | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share warrant price (in Euro per share)	0.11
Fair value per warrant (in Euro per share)	€ 0.38
Plan C
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	2 years
Contractual life (in years)	10 years
Number of grants (in shares)	192,000,000
Share entitlement per warrant (in shares)	1
Plan C | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share warrant price (in Euro per share)	€ 0.04
Exercise price (in Euro per share)	0.70
Grant date share fair value (in Euro per share)	€ 0.70
Expected volatility rate	53.50%
Discount rate	2.62%
Fair value per warrant (in Euro per share)	€ 0.40
Plan C | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share warrant price (in Euro per share)	0.30
Exercise price (in Euro per share)	5.95
Grant date share fair value (in Euro per share)	€ 4.98
Expected volatility rate	55.00%
Discount rate	3.38%
Fair value per warrant (in Euro per share)	€ 2.58
Plan D
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	2 years
Contractual life (in years)	10 years
Number of grants (in shares)	125,784,000
Share entitlement per warrant (in shares)	1
Plan D | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share warrant price (in Euro per share)	€ 0.43
Exercise price (in Euro per share)	8.28
Grant date share fair value (in Euro per share)	€ 6.43
Expected volatility rate	50.00%
Discount rate	2.13%
Fair value per warrant (in Euro per share)	€ 2.85
Plan D | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share warrant price (in Euro per share)	0.48
Exercise price (in Euro per share)	9.65
Grant date share fair value (in Euro per share)	€ 9.65
Expected volatility rate	50.20%
Discount rate	2.27%
Fair value per warrant (in Euro per share)	€ 4.98
Plan E
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)	10 years
Number of grants (in shares)	38,070,000
Share entitlement per warrant (in shares)	1
Expected volatility rate	39.90%
Plan E | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Share warrant price (in Euro per share)	€ 9.98
Exercise price (in Euro per share)	35.18
Grant date share fair value (in Euro per share)	€ 35.18
Discount rate	0.00%
Fair value per warrant (in Euro per share)	€ 9.98
Plan E | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Share warrant price (in Euro per share)	€ 16.82
Exercise price (in Euro per share)	41.02
Grant date share fair value (in Euro per share)	€ 41.02
Discount rate	0.52%
Fair value per warrant (in Euro per share)	€ 16.82
Plan F
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)	10 years
Number of grants (in shares)	48,655,000
Share entitlement per warrant (in shares)	1
Expected volatility rate	40.60%
Plan F | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Share warrant price (in Euro per share)	€ 13.89
Exercise price (in Euro per share)	33.98
Grant date share fair value (in Euro per share)	€ 33.98
Discount rate	0.10%
Fair value per warrant (in Euro per share)	€ 13.89
Plan F | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	4 years
Share warrant price (in Euro per share)	€ 14.55
Exercise price (in Euro per share)	35.41
Grant date share fair value (in Euro per share)	€ 35.41
Discount rate	0.25%
Fair value per warrant (in Euro per share)	€ 14.55

Share-Based Compensation - C101

Share-Based Compensation - Changes in Number of Non-Employee Warrants (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Exercised (in shares)	(1,470,323)	(1,533,616)	(3,175,843)
BSA
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Beginning balance, options (in shares)	154,910	199,408	542,148
Options granted (in shares)	48,655	38,070	5,040
Exercised (in shares)	(37,000)	(34,568)	(345,780)
Forfeited (in shares)	21,560	(48,000)	(2,000)
Ending balance, options (in shares)	188,125	154,910	199,408

Share-Based Compensation - B102

Share-Based Compensation - Breakdown of Closing Balance of Non-Employee Warrants (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2016$ / sharesshares	Dec. 31, 2015$ / sharesshares	Dec. 31, 2014$ / sharesshares	Dec. 31, 2016€ / sharesshares	Dec. 31, 2015€ / sharesshares	Dec. 31, 2014€ / sharesshares	Dec. 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, weighted-average exercise price, options (in Euro per share) | € / shares				€ 23.92	€ 20.97	€ 14.10
Exercisable, weighted-average exercise price, options (in Euro per share) | € / shares				€ 17.73	€ 11.85	€ 5.81
Weighted-average remaining contractual life, options (in years)	6 years 10 months 24 days	7 years 10 months 24 days	8 years 2 months 12 days
BSA
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number outstanding, options (in shares) | shares	188,125	154,910	199,408	188,125	154,910	199,408	542,148
Outstanding, weighted-average exercise price, options (in Euro per share) | $ / shares	$ 19.04	$ 15.72	$ 7.54
Number of exercisable options (in shares) | shares	117,096	117,783	155,609	117,096	117,783	155,609
Exercisable, weighted-average exercise price, options (in Euro per share) | $ / shares	$ 11.73	$ 8.49	$ 6.88
Weighted-average remaining contractual life, options (in years)	7 years 3 months 18 days	7 years 4 months 24 days	7 years 6 months

Share-Based Compensation - Shar

Share-Based Compensation - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ (41,589)	$ (23,743)	$ (19,469)
Equity awards compensation expense	(43,259)	(23,989)	(19,600)
R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(12,108)	(6,520)	(3,682)
Equity awards compensation expense	(12,108)	(6,520)	(3,682)
S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(16,838)	(11,678)	(12,290)
Equity awards compensation expense	(16,838)	(11,678)	(12,290)
G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(12,643)	(5,545)	(3,497)
Equity awards compensation expense	(14,313)	(5,791)	(3,628)
RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(29,170)	(2,296)	0
RSUs | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(9,178)	(706)	0
RSUs | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(12,705)	(1,046)	0
RSUs | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(7,287)	(544)	0
OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(12,419)	(21,447)	(19,469)
OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(2,930)	(5,814)	(3,682)
OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(4,133)	(10,632)	(12,290)
OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(5,356)	(5,001)	(3,497)
Plan 3 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	0	(5)	13
Plan 3 | OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	0	1	34
Plan 3 | OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	0	(6)	15
Plan 3 | OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	0	0	(36)
Plan 5 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(42)	(152)	(606)
Plan 5 | OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(8)	(71)	(215)
Plan 5 | OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(27)	27	(134)
Plan 5 | OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(7)	(108)	(257)
Plan 6 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(217)	(585)	(1,907)
Plan 6 | OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(35)	(188)	(505)
Plan 6 | OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(20)	(384)	(1,358)
Plan 6 | OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(162)	(13)	(44)
Plan 7 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(189)	(3,021)	(11,226)
Plan 7 | OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(234)	(884)	(1,598)
Plan 7 | OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	239	(1,758)	(8,494)
Plan 7 | OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(194)	(379)	(1,134)
Plan 8 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(11,483)	(17,684)	(5,743)
Plan 8 | OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(2,587)	(4,672)	(1,398)
Plan 8 | OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(4,258)	(8,511)	(2,319)
Plan 8 | OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(4,638)	(4,501)	(2,026)
Plan 9 | OSA and BSPCE
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(488)	0	0
Plan 9 | OSA and BSPCE | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(66)	0	0
Plan 9 | OSA and BSPCE | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(67)	0	0
Plan 9 | OSA and BSPCE | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	(355)	0	0
BSA | BSA
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Issuance of non-employee warrants	(1,670)	(246)	(131)
BSA | BSA | R&D
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Issuance of non-employee warrants	0	0	0
BSA | BSA | S&O
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Issuance of non-employee warrants	0	0	0
BSA | BSA | G&A
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Issuance of non-employee warrants	$ (1,670)	$ (246)	$ (131)

Financial Income and Expenses -

Financial Income and Expenses - Financial income (expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Income and Expenses [Abstract]
Financial income from cash equivalents	$ 1,352	$ 2,105	$ 1,910
Interest and fees	(2,367)	(653)	(583)
Interest on debt	(1,134)	(553)	(583)
Fees	(1,233)	(100)	0
Foreign exchange (loss) gain	506	(5,971)	10,096
Other financial expense	(37)	(22)	(33)
Total financial income (expense)	$ (546)	$ (4,541)	$ 11,390

Financial Income and Expense105

Financial Income and Expenses - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Financial income (expense)	$ 546	$ 4,541	$ (11,390)
Foreign exchange (loss) gain	$ 506	(5,971)	$ 10,096
IPO
Class of Stock [Line Items]
Gain on sale of stock		2,100
Proceeds from IPO		$ 70,000

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Current income tax	$ (43,153)	$ (25,265)	$ (22,893)
France	(20,204)	(15,458)	(11,087)
International	(22,949)	(9,807)	(11,806)
Net change in deferred taxes	10,024	15,748	5,315
France	2,654	2,009	671
International	7,370	13,739	4,644
Provision for income tax	$ (33,129)	$ (9,517)	$ (17,578)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Current federal tax expense (benefit), value added taxes	$ 4,100	$ 3,000	$ 2,500
Theoretical group tax-rates	34.43%	34.43%	34.43%
Deferred tax assets, valuation allowance	$ 19,821	$ 23,980	$ 19,863
Duration of tax plan (in years)	3 years
Deferred tax assets, changes related to recognition of deferred tax assets	$ 8,500
Foreign Tax Authority | America - IRS
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, subject to expiration	14,900
Foreign Tax Authority | China - State Administration of Taxation
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, subject to expiration	3,600
Foreign Tax Authority | United Kingdom - HMRC
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, not subject to expiration	4,800
Criteo Corp., Criteo Do Brasil, Criteo Ltd and Criteo Advertising (Beijing) Co. Ltd
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	19,900	24,000	26,100
Criteo Corp
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	900	12,400	13,900
Criteo Do Brasil
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	3,600	3,900	2,600
Criteo Ltd
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	4,700	4,700	7,700
Criteo China
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	3,700	1,400	700
Criteo France
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	$ 3,000	$ 600	$ 700

Income Taxes - Reconciliation B

Income Taxes - Reconciliation Between the Effective and Nominal Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income before taxes	$ 120,458	$ 71,793	$ 64,474
Theoretical group tax-rates	34.43%	34.43%	34.43%
Nominal tax expense	$ (41,474)	$ (24,718)	$ (22,198)
Increase / decrease in tax expense arising from:
Research tax credit	1,701	1,352	1,743
Net effect of shared based compensation	(8,957)	2,048	3,419
Other permanent differences	(3,518)	(804)	(2,245)
Non recognition of deferred tax assets related to tax losses and temporary differences	(7,738)	(7,662)	(3,546)
Utilization or recognition of previously unrecognized tax losses	13,366	12,264	276
French CVAE included in income taxes	(3,165)	(3,052)	(2,467)
Special tax deductions	20,022	12,545	8,984
Effect of different tax rates	(1,108)	(1,046)	(1,019)
Other differences	(2,258)	(444)	(525)
Provision for income tax	$ (33,129)	$ (9,517)	$ (17,578)
Effective tax rate	27.50%	13.30%	27.30%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax assets (gross), beginning balance	$ 46,238	$ 30,221
Valuation allowance, beginning balance	(23,980)	(19,863)
Deferred tax asset (net), beginning balance	22,258	10,358
Net deferred income tax balance, beginning balance	20,057	7,493
Change recognized in profit or loss	10,024	15,748	$ 5,315
Change recognized in OCI	(27)	(23)
Change in consolidation scope	0	(3,120)
Other	0	0
Currency translation adjustments	(110)	(41)
Deferred tax assets (gross), ending balance	53,240	46,238	30,221
Valuation allowance, ending balance	(19,821)	(23,980)	(19,863)
Deferred tax asset (net), ending balance	33,419	22,258	10,358
Net deferred income tax balance, ending balance	29,944	20,057	7,493
Net operating loss carryforwards
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax assets (gross), beginning balance	28,423	23,468
Change recognized in profit or loss	(1,048)	(385)
Change recognized in OCI	0	0
Change in consolidation scope	0	5,889
Other	0	0
Currency translation adjustments	(912)	(549)
Deferred tax assets (gross), ending balance	26,463	28,423	23,468
Personnel-related accruals
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax assets (gross), beginning balance	7,302	2,538
Change recognized in profit or loss	257	5,414
Change recognized in OCI		0
Change in consolidation scope	0	9
Other	(30)	0
Currency translation adjustments	241	(659)
Deferred tax assets (gross), ending balance	7,770	7,302	2,538
Other accruals
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax assets (gross), beginning balance	3,093	2,285
Change recognized in profit or loss	975	1,353
Change recognized in OCI		0
Change in consolidation scope	0	0
Other	30	0
Currency translation adjustments	276	(545)
Deferred tax assets (gross), ending balance	4,374	3,093	2,285
Projected benefit obligation
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax assets (gross), beginning balance	578	472
Change recognized in profit or loss	213	202
Change recognized in OCI	466	(44)
Change in consolidation scope	0	0
Other	0	0
Currency translation adjustments	(50)	(52)
Deferred tax assets (gross), ending balance	1,207	578	472
Other
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax assets (gross), beginning balance	6,842	1,458
Change recognized in profit or loss	7,331	4,372
Change recognized in OCI	0	0
Change in consolidation scope	0	1,091
Other	(482)	0
Currency translation adjustments	(265)	(79)
Deferred tax assets (gross), ending balance	13,426	6,842	1,458
Deferred tax assets (gross)
Deferred Tax Asset and Liability Activity [Roll Forward]
Change recognized in profit or loss	7,728	10,956
Change recognized in OCI	466	(44)
Change in consolidation scope	0	6,989
Other	(482)	0
Currency translation adjustments	(710)	(1,884)
Valuation allowance
Deferred Tax Asset and Liability Activity [Roll Forward]
Change recognized in profit or loss	3,630	1,429
Change recognized in OCI	(16)	21
Change in consolidation scope	0	(7,177)
Other	0	0
Currency translation adjustments	545	1,610
Deferred tax asset (net)
Deferred Tax Asset and Liability Activity [Roll Forward]
Change recognized in profit or loss	11,358	12,385
Change recognized in OCI	450	(23)
Change in consolidation scope	0	(188)
Other	(482)	0
Currency translation adjustments	(165)	(274)
Intangible assets
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax liabilities, beginning balance	(150)	(2,861)
Change recognized in profit or loss	(6)	5,445
Change recognized in OCI	(477)	0
Change in consolidation scope	0	(2,979)
Other	(33)	0
Currency translation adjustments	35	245
Deferred tax liabilities, ending balance	(631)	(150)	(2,861)
Other
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax liabilities, beginning balance	(2,051)	(4)
Change recognized in profit or loss	(1,328)	(2,082)
Change recognized in OCI	0	0
Change in consolidation scope	0	47
Other	515	0
Currency translation adjustments	20	(12)
Deferred tax liabilities, ending balance	(2,844)	(2,051)	(4)
Deferred tax liabilities
Deferred Tax Asset and Liability Activity [Roll Forward]
Deferred tax liabilities, beginning balance	(2,201)	(2,865)
Change recognized in profit or loss	(1,334)	3,363
Change recognized in OCI	(477)	0
Change in consolidation scope	0	(2,932)
Other	482	0
Currency translation adjustments	55	233
Deferred tax liabilities, ending balance	$ (3,475)	$ (2,201)	$ (2,865)

Earnings Per Share - Basic Earn

Earnings Per Share - Basic Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income attributable to shareholders of Criteo S.A.	$ 82,272	$ 59,553	$ 45,556
Weighted average shares outstanding, basic (in shares)	63,337,792	61,835,499	58,928,563
Basic earnings per share (in dollars per share)	$ 1.30	$ 0.96	$ 0.77

Earnings Per Share - Diluted Ea

Earnings Per Share - Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income attributable to shareholders of Criteo S.A.	$ 82,272	$ 59,553	$ 45,556
Weighted average shares outstanding, basic (in shares)	63,337,792	61,835,499	58,928,563
Dilutive effect of :
Restricted share awards (in shares)	253,728	0	0
Share options and BSPCE (in shares)	1,958,728	3,133,549	4,347,236
Share warrants (in shares)	83,222	127,438	217,461
Weighted average number of shares outstanding used to determine diluted earnings per share (in shares)	65,633,470	65,096,486	63,493,260
Diluted earnings per share (in dollars per share)	$ 1.25	$ 0.91	$ 0.72

Earnings Per Share - Weighted A

Earnings Per Share - Weighted Average Number of Anti-Dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share	905,528	1,258,555	1,288,977
Restricted share awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share	396,086	273,896	0
Share options and BSPCE
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share	509,442	968,734	1,288,977
Share warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average number of anti-dilutive securities excluded from diluted earnings per share	0	15,925	0

Commitments and contingencies -

Commitments and contingencies - Schedule of Future Minimum Payments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Minimum payments for property leases
Loss Contingencies [Line Items]
Less than 1 year	$ 33,655
1 to 5 years	98,938
5 plus years	49,551
Total	182,144
Minimum payments for hosting services
Loss Contingencies [Line Items]
Less than 1 year	50,959
1 to 5 years	48,927
5 plus years	0
Total	99,886
Minimum payments for other leases
Loss Contingencies [Line Items]
Less than 1 year	4,197
1 to 5 years	4,912
5 plus years	0
Total	$ 9,109

Commitments and contingencie114

Commitments and contingencies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2016CNY (¥)	Dec. 31, 2016EUR (€)	Dec. 31, 2016USD ($)	Sep. 30, 2015EUR (€)	Sep. 30, 2015USD ($)	May 31, 2015CNY (¥)	May 31, 2015USD ($)	Oct. 31, 2014CNY (¥)
Revolving Credit Facility | Line of Credit | BPI France Revolving Credit Facility
Loss Contingencies [Line Items]
Long-term line of credit					€ 100,000	$ 100,000
Maximum borrowing capacity					1,000,000	1,100,000
Revolving Credit Facility | Line of Credit | HSBC Revolving Loan Facility
Loss Contingencies [Line Items]
Long-term line of credit				¥ 30,000,000		4,300,000
Maximum borrowing capacity				¥ 40,000,000		5,800,000			¥ 40,000,000	$ 5,800,000	¥ 15,000,000
Revolving Credit Facility | Line of Credit | Bank Syndicate RCF
Loss Contingencies [Line Items]
Long-term line of credit						75,000,000
Maximum borrowing capacity					250,000,000	263,500,000	€ 250,000,000	$ 263,500,000
Line of Credit and Overdraft Facility | HSBC and LCL Facilities | Line of Credit
Loss Contingencies [Line Items]
Maximum borrowing capacity					€ 9,400,000	$ 9,900,000
Property Leases
Loss Contingencies [Line Items]
Operating lease expense	$ 32,100,000	$ 23,600,000	$ 18,800,000
Hosting Services
Loss Contingencies [Line Items]
Operating lease expense	$ 42,000,000	$ 30,400,000	$ 24,800,000

Related Parties (Details)

Related Parties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Share-based compensation	$ (41,589)	$ (23,743)	$ (19,469)
Personnel expenses	(332,353)	(246,171)	(189,418)
Executive Officer
Related Party Transaction [Line Items]
Short-term benefits	(2,755)	(3,067)	(4,145)
Long-term benefits	(194)	(245)	(241)
Share-based compensation	(7,159)	(4,594)	(3,291)
Personnel expenses	$ (10,108)	$ (7,906)	$ (7,677)

Breakdown of Revenue and Non116

Breakdown of Revenue and Non-Current Assets by Geographical Areas - Revenue by Geographical Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,799,146	$ 1,323,169	$ 988,249
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	730,873	505,653	303,436
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	660,523	541,105	485,986
Asia-Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 407,750	$ 276,411	$ 198,827

Breakdown of Revenue and Non117

Breakdown of Revenue and Non-Current Assets by Geographical Areas - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,799,146	$ 1,323,169	$ 988,249
France
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 132,200	$ 116,800	$ 115,400

Breakdown of Revenue and Non118

Breakdown of Revenue and Non-Current Assets by Geographical Areas - Revenue by Significant Other Countries (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 1,799,146	$ 1,323,169	$ 988,249
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	630,047	419,742	237,385
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	137,116	111,792	105,544
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	115,053	107,071	90,315
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 285,959	$ 190,066	$ 154,798

Breakdown of Revenue and Non119

Breakdown of Revenue and Non-Current Assets by Geographical Areas - Other Information (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	$ 131,525	$ 98,952
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	43,308	24,437
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	42,474	23,332
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	7,132	8,847
Asia-Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	26,033	17,508
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	8,965	7,807
Holding
Revenues from External Customers and Long-Lived Assets [Line Items]
Non-current assets	$ 55,052	$ 48,160