Goodwill and Intangible Assets (Detail) - Carrying Amounts of Amortizable Intangible Assets - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Finite-lived Intangible Assets [Roll Forward]
Gross carrying amount	$ 116,767
Finite-lived Intangible Assets Acquired	10,500
Foreign currency translation impact	314
Gross carrying amount	127,581
Accumulated amortization	(46,372)		$ (39,966)
Finite-lived intangible assets, net	81,209		76,801
Amortization of intangibles	6,290	$ 6,183
Trade Name
Finite-lived Intangible Assets [Roll Forward]
Gross carrying amount	4,337
Finite-lived Intangible Assets Acquired	500
Foreign currency translation impact	20
Gross carrying amount	4,857
Accumulated amortization	(2,046)		(1,737)
Finite-lived intangible assets, net	$ 2,811		2,600
Trade Name | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	4 years
Trade Name | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	2 years
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Gross carrying amount	$ 63,369
Finite-lived Intangible Assets Acquired	9,000
Foreign currency translation impact	190
Gross carrying amount	72,559
Accumulated amortization	(19,469)		(16,744)
Finite-lived intangible assets, net	$ 53,090		46,625
Customer Relationships | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	4 years
Customer Relationships | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	8 years
Content
Finite-lived Intangible Assets [Roll Forward]
Gross carrying amount	$ 3,728
Finite-lived Intangible Assets Acquired	0
Foreign currency translation impact	37
Gross carrying amount	3,765
Accumulated amortization	(2,521)		(2,033)
Finite-lived intangible assets, net	$ 1,244		1,695
Content | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	1 year 6 months
Content | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	2 years
Software
Finite-lived Intangible Assets [Roll Forward]
Gross carrying amount	$ 16,025
Finite-lived Intangible Assets Acquired	1,000
Foreign currency translation impact	42
Gross carrying amount	17,067
Accumulated amortization	(10,266)		(8,904)
Finite-lived intangible assets, net	$ 6,801		7,121
Finite-lived intangible assets useful life	3 years
Non-Compete
Finite-lived Intangible Assets [Roll Forward]
Gross carrying amount	$ 29,308
Finite-lived Intangible Assets Acquired	0
Foreign currency translation impact	25
Gross carrying amount	29,333
Accumulated amortization	(12,070)		(10,548)
Finite-lived intangible assets, net	$ 17,263		$ 18,760
Non-Compete | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	3 years
Non-Compete | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	5 years