Income Taxes - Rollforward of Total Gross Unrecognized Tax Benefit (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
Unrecognized tax benefit as of beginning of period | $ 33,067 | $ 26,668 | |
Tax positions related to current year, additions for uncertain tax positions | 6,346 | 6,659 | $ 6,110 |
Tax positions related to prior year, additions for uncertain tax positions | (260) | (81) | |
Decreases for uncertain tax positions | 0 | ||
Unrecognized tax benefit as of end of period | $ 39,413 | $ 33,067 | $ 26,668 |