Business and Significant Accounting Policies (Detail) - Intangible Assets Subject to Amortization - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-lived Intangible Assets [Roll Forward]
Gross cost	$ 118,003	$ 54,258
Additions due to acquisitions	5,927	79,611
Finite-Lived Intangible Assets, Fully Amortized Intangibles	(287)	(13,223)
Foreign currency translation impact	(6,876)	(2,643)
Gross cost	116,767	118,003
Accumulated amortization	(39,966)	(21,459)
Finite-lived intangible assets, net	76,801	96,544
Trade Names
Finite-lived Intangible Assets [Roll Forward]
Gross cost	4,144	6,924
Additions due to acquisitions	302	3,260
Finite-Lived Intangible Assets, Fully Amortized Intangibles	0	(6,013)
Foreign currency translation impact	(109)	(27)
Gross cost	4,337	4,144
Accumulated amortization	(1,737)	(681)
Finite-lived intangible assets, net	2,600	3,463
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Gross cost	62,860	27,933
Additions due to acquisitions	3,677	42,620
Finite-Lived Intangible Assets, Fully Amortized Intangibles	0	(7,210)
Foreign currency translation impact	(3,168)	(483)
Gross cost	63,369	62,860
Accumulated amortization	(16,744)	(9,028)
Finite-lived intangible assets, net	46,625	53,832
Content
Finite-lived Intangible Assets [Roll Forward]
Gross cost	5,450	3,560
Additions due to acquisitions	1,948	2,000
Finite-Lived Intangible Assets, Fully Amortized Intangibles	(162)	0
Foreign currency translation impact	(3,508)	(110)
Gross cost	3,728	5,450
Accumulated amortization	(2,033)	(3,525)
Finite-lived intangible assets, net	1,695	1,925
Software
Finite-lived Intangible Assets [Roll Forward]
Gross cost	16,219	6,569
Additions due to acquisitions	0	11,656
Finite-Lived Intangible Assets, Fully Amortized Intangibles	(125)	0
Foreign currency translation impact	(69)	(2,006)
Gross cost	16,025	16,219
Accumulated amortization	(8,904)	(3,699)
Finite-lived intangible assets, net	7,121	12,520
Non-Compete
Finite-lived Intangible Assets [Roll Forward]
Gross cost	29,330	9,272
Additions due to acquisitions	0	20,075
Finite-Lived Intangible Assets, Fully Amortized Intangibles	0	0
Foreign currency translation impact	(22)	(17)
Gross cost	29,308	29,330
Accumulated amortization	(10,548)	(4,526)
Finite-lived intangible assets, net	$ 18,760	$ 24,804