Income Tax - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Operating expenses not currently deductible	$ 10,214	$ 8,989
Stock option and other employee benefit plans	19,308	19,496
Loss and credit carryforwards	23,841	17,999
Total deferred income tax assets	53,363	46,484
Valuation allowance	(1,923)	(1,049)
Total deferred income tax assets, net of valuation allowance	51,440	45,435
Intangible assets	(84,019)	(70,752)
Property and equipment	(9,265)	(8,455)
Prepaid expenses	(4,922)	(4,079)
Deferred revenue	(1,676)	(3,940)
Total deferred income tax liabilities	(99,882)	(87,226)
Net deferred income tax liabilities	$ (48,442)	$ (41,791)