Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
Mar. 31, 2017 |
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||||
| Income tax expense | $ 123 | $ (4,160) | $ (7,702) | $ (2,716) | |
| Accounting Standards Update 2016-09 [Member] | |||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||||
| Deferred tax liability | $ 1,000 | ||||
| Income tax expense | $ 1,500 | ||||
| Retained Earnings [Member] | Accounting Standards Update 2016-09 [Member] | |||||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||||
| Cumulative effect adjustment | $ 1,000 | ||||