Commitments and Contingencies - Summary of Lease Exit Accruals (Detail) $ in Thousands  | 
12 Months Ended | 
|---|---|
| 
 Dec. 31, 2016  
USD ($) 
 | |
| Commitments And Contingencies Disclosure [Abstract] | |
| Beginning balance | $ 14,527 | 
| Lease exit expense | 1,386 | 
| Payments | (6,123) | 
| Ending balance | $ 9,790 | 
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- Definition Lease exit accruals. No definition available. 
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- Definition Lease exit expense. No definition available. 
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- Definition Lease exit payment. No definition available. 
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- References No definition available. 
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