Income Taxes - Reconciliation Of The Statutory Federal Income Tax Expense And The Company's Total Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal income tax expense	$ 25	$ 10,718	$ 20,367
Change in valuation allowance – Capital losses(1)	7,555	794
Change in valuation allowance -Foreign	4,737	3,510	5,355
Decrease in unrecognized tax benefits	(3,894)
Foreign operations	(3,561)	(1,041)	(165)
Loss/(gain) on revaluation of deferred consideration(2)	2,378	(2,570)
Non-deductible executive compensation	1,608	4
Stock-based compensation tax (windfalls)/shortfalls	1,198	(543)	1,035
Blended state income tax rate, net of federal benefit	237	1,406	2,234
Non-deductible acquisition and disposition-related costs		1,506	1,549
Other differences, net	263	622	618
Income tax expense	$ 10,546	$ 14,406	$ 30,993