Income Taxes - Schedule of Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Income Tax Disclosure [Abstract] | |||
Gross unrecognized tax benefits, beginning of the year | $ 8,564 | $ 8,132 | $ 7,737 |
Additions for tax positions of prior years | 5 | 24 | 263 |
Additions for tax positions related to the current year | 1,839 | 1,625 | 1,247 |
Reductions due to lapse of applicable statute of limitations | (1,399) | (1,217) | (1,115) |
Subtotal | 9,009 | 8,564 | 8,132 |
Interest and penalties | 1,862 | 1,909 | 2,008 |
Total gross unrecognized tax benefits, end of the year | $ 10,871 | $ 10,473 | $ 10,140 |