Income Taxes - Reconciliation of Federal Statutory Income Tax Provision (Benefit) to Effective Income Tax Provision (Detail) - USD ($) $ in Thousands			12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Expected provision for (benefit from) income taxes at U.S. federal statutory rate			$ 9,940	$ 5,557	$ 13,154
State income taxes, net of federal benefit			4,743	205	142
BEAT obligation				3,918
Income (loss) taxed at foreign rates			10,292	4,447	(3,643)
Stock-based compensation			(15,683)	(3,457)	(2,898)
Tax reserve for uncertain tax positions			3,174	1,676	3,101
Change in valuation allowance			(56,194)	(5,610)	(51,976)
Impact of 2017 Tax Act					48,237
Acquisition costs			1,166	536
Contingent consideration			42,328	1,155	(252)
Officer's compensation limitation			5,165	2,340	2,582
Investment in subsidiaries					1,676
Other			479	239	821
Provision for (benefit from) income taxes	$ (14,800)	$ (9,200)	$ 5,410	$ 11,006	$ 10,944