Income Taxes - Summary of Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating losses and credit carryforwards	$ 64,881	$ 41,447
Stock options	12,394	8,133
Deferred rent	2,887	2,536
Deferred revenue	0	1
Accrued expenses	8,486	9,362
Tax credits	2,338	0
Other	7	0
Total deferred tax assets	90,993	61,479
Valuation allowance	(127)	(512)
Net deferred tax assets	90,866	60,967
Deferred tax liabilities:
Property, equipment, and intangibles	(12,826)	(16,620)
Other	(677)	(610)
Total deferred tax liabilities	(13,503)	(17,230)
Net deferred tax assets	$ 77,363	$ 43,737