XML 100 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes - Schedule of Company's Deferred Tax Assets (Detail) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Deferred tax assets:    
Net operating loss carryforwards $ 91,308 $ 114,222
Research and development tax credit carryforwards 15,147 12,518
Stock-based compensation 3,168 8,565
Deferred revenue 934 2,918
Other 2,276 3,492
Total deferred tax asset 112,833 141,715
Valuation allowance $ 112,833 $ 141,715