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Stock-Based Awards - Additional Information (Detail) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jun. 20, 2016 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
PRSU |  |  |  |  |
Shares of common stock authorized to issue under equity award plan | 10,000,000 |  |  |  |
Stock-based compensation expense |  | $ 2,374 | $ 3,240 | $ 8,581 | $ 10,078
Below 25th Percentile [Member] |  |  |  |  |
PRSU |  |  |  |  |
Shares granted and outstanding, Vesting percentage |  |  |  | 0.00% |
Above 25th Percentile [Member] |  |  |  |  |
PRSU |  |  |  |  |
Shares granted and outstanding, Vesting percentage |  |  |  | 50.00% |
At 50th Percentile [Member] |  |  |  |  |
PRSU |  |  |  |  |
Shares granted and outstanding, Vesting percentage |  |  |  | 100.00% |
At 100th Percentile [Member] |  |  |  |  |
PRSU |  |  |  |  |
Shares granted and outstanding, Vesting percentage |  |  |  | 200.00% |
Performance Based Restricted Stock Unit [Member] | Maximum [Member] |  |  |  |  |
PRSU |  |  |  |  |
Shares granted and outstanding, Vesting percentage |  |  |  | 200.00% |
Performance Based Restricted Stock Unit [Member] | Minimum [Member] |  |  |  |  |
PRSU |  |  |  |  |
Shares granted and outstanding, Vesting percentage |  |  |  | 0.00% |

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