Commitments and Contingencies - Additional Information Operating Leases (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Commitments and Contingencies Disclosure [Abstract] | |||
| Deferred rent | $ 4.8 | $ 4.3 | |
| Rental expense | $ 25.6 | $ 23.4 | $ 17.8 |
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- References No definition available.
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- Definition The cumulative difference between the rental payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense over the term of the leased property by the lessor or lessee, respectively. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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