Income Taxes - Summary of Deferred Tax Assets and Deferred Tax Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Stock-based compensation	$ 30,081	$ 21,605
Net operating loss carryforwards	18,005	15,005
Provision for accrued expenses	6,829	7,731
Other	4,365	3,391
Total deferred tax assets	59,280	47,732
Less valuation allowance	(13,284)	(11,677)
Net deferred tax assets	45,996	36,055
Deferred tax liabilities:
Intangible assets	(31,956)	(28,205)
Property and equipment	(17,500)	(10,313)
Prepaid expenses	(2,010)	(2,087)
Other	(2,201)
Total deferred tax liabilities	(53,667)	(40,605)
Net deferred tax liability	$ (7,671)	$ (4,550)