Income Taxes - Reconciliation of Valuation Allowance (Detail) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | ||
---|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
Valuation Allowance [Line Items] | ||||
Balance at the beginning of the period | $ 140,915 | $ 154,252 | $ 152,138 | |
Charged to provision for income taxes | 2,305 | (13,292) | 2,704 | |
Foreign currency | (313) | 45 | 590 | |
Deductions | 0 | 0 | 0 | |
Release valuation allowance | $ 141,100 | 141,094 | ||
Balance at the end of the period | $ 5,368 | $ 5,368 | 140,915 | $ 154,252 |
Accounting Standards Update 2016-09 | ||||
Valuation Allowance [Line Items] | ||||
Adoption of ASU 2016-09 | $ 2,929 |