Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Disclosure Income Taxes Summary Of Deferred Tax Assets And Liabilities [Abstract]
Accounts receivable, principally due to the allowance for doubtful accounts	$ 4,451	$ 4,028
Accrued expenses not currently deductible for tax		2,257
Stock based compensation	12,022	8,226
Foreign tax credit	1,349	177
Net operating loss carry forwards	4,438	4,291
Fixed assets	4,135	580
Other	541	643
Deferred tax assets before valuation allowance	26,936	20,202
Valuation allowance	(1,450)	(1,382)
Deferred tax assets, net	25,486	18,820
Property and equipment, principally due to differences between book and tax depreciation	(4,180)
Intangibles-including goodwill	(226,396)	(165,270)
Basis difference in investment in foreign subsidiaries	(25,145)	(26,926)
Other	(14,519)	(769)
Deferred tax liabilities	(270,240)	(192,965)
Net deferred tax liabilities	$ (244,754)	$ (174,145)