Income Taxes - Rollforward of Total Gross Unrecognized Tax Benefit (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
Unrecognized tax benefit as of beginning of period | $ 47,656 | $ 46,384 | $ 39,413 |
Tax positions related to current year, additions for uncertain tax positions | 14,519 | 1,819 | 6,971 |
Tax positions related to prior year, Additions for uncertain tax positions | 80 | 1,809 | |
Tax positions related to prior year, Decreases for uncertain tax positions | (826) | ||
Tax positions related to prior year, Settlements with tax authorities | (1,527) | ||
Tax positions related to prior year, Reductions due to lapse of applicable statute of limitations | (28,993) | (3) | |
Unrecognized tax benefit as of end of period | $ 33,262 | $ 47,656 | $ 46,384 |