Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating loss (“NOL”) carryforwards	$ 74,486	$ 69,176
Accrued expenses, reserves and allowances	940	1,220
Deferred revenue	16,545	16,429
Tax credit carryforwards	12,079	9,580
Deferred rent	320	363
Depreciation	820	0
Amortizable intangibles	203	0
Other	16,333	13,840
Total deferred tax assets	121,726	110,608
Deferred tax liabilities:
Depreciation	0	(1,212)
Amortizable intangibles	0	(1,678)
Indefinite lived intangibles	(367)	(238)
Other	0	(177)
Total deferred tax liabilities	(367)	(3,305)
Valuation allowance	(121,726)	(107,540)
Net deferred taxes	$ (367)	$ (237)