Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss and credit carryforwards	$ 84,684	$ 97,154
Capital loss	22,948	23,008
Accrued compensation	6,686	5,526
Stock-based compensation	4,986	3,971
Deferred revenue	4,042	3,700
Lease liability	2,133	0
Other, net	3,833	2,143
Total gross deferred tax assets	129,312	135,502
Valuation allowance	(43,824)	(100,705)	$ (109,242)	$ (226,813)
Deferred tax assets, net of valuation allowance	85,488	34,797
Deferred tax liabilities:
Amortization	(69,668)	(72,563)
Depreciation	(2,521)	(1,572)
Right-of-use assets	2,382	0
Other, net	(920)	(1,056)
Total gross deferred tax liabilities	75,491	75,191
Net deferred tax assets (liabilities)	$ 9,997
Net deferred tax assets (liabilities)		$ (40,394)