Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Disclosure Income Taxes Summary Of Deferred Tax Assets And Liabilities [Abstract]
Accounts receivable, principally due to the allowance for doubtful accounts	$ 6,277	$ 7,434
Accrued expenses not currently deductible for tax	5,797	5,610
Stock based compensation	35,066	16,405
Income tax credits	3,830	3,830
Net operating loss carry forwards	39,970	127,487
Equity investment	38,760	3,262
Accrued escheat	13,497	12,058
Fixed assets, intangibles and other	14,191	12,868
Deferred tax assets before valuation allowance	157,388	188,954
Valuation allowance	(62,605)	(27,082)
Deferred tax assets, net	94,783	161,872
Intangibles-including goodwill	(732,017)	(818,680)
Basis difference in investment in foreign subsidiaries	(47,737)	(23,128)
Property and equipment, principally due to differences between book and tax depreciation, and other	(19,544)	(18,552)
Deferred tax liabilities	(799,298)	(860,360)
Net deferred tax liabilities	$ (704,515)	$ (698,488)