Business Combination - Additional Information (Details) $ in Thousands, € in Millions				12 Months Ended
	Nov. 09, 2016 USD ($)	May 31, 2016 EUR (€)	May 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 EUR (€)	Dec. 31, 2016 USD ($)	May 31, 2016 USD ($)
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							€ 75.0	$ 75,000
Revolving Credit Facility | Bank Syndicate RCF | Line of Credit | HookLogic, Inc.
Business Acquisition [Line Items]
Amount drawn	$ 75,000