Schedule of Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Components Of Deferred Tax Assets And Liabilities [Abstract]
Deferred tax assets, Net operating loss carryforwards	$ 874	$ 841
Deferred tax assets, Tax credits	2,553	1,839
Deferred tax assets, Intangible assets	1,878	0
Deferred tax assets, Deferred revenue adjustment	423	543
Deferred tax assets, Accrued Compensation	6,257	6,519
Share-based compensation expense	14,182	12,987
Deferred tax assets, Deferred rent	1,330	1,764
Deferred tax assets, Other	1,453	2,115
Deferred tax assets before valuation allowance	28,950	26,608
Deferred tax assets, Valuation allowance	(2,130)	(1,507)
Deferred tax assets, net of valuation allowance	26,820	25,101
Deferred tax liabilities, Prepaid expenses and other	1,693	1,049
Deferred tax liabilities, Property and equipment	5,092	5,841
Method change	652	932
Total deferred tax liabilities	7,437	7,822
Total net deferred tax asset	19,383	17,279
Non-current deferred tax assets, net	19,409	17,316
Non-current deferred tax liabilities	$ (26)	$ (37)