| Accounting for Uncertainty in Income Taxes - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended | 
|---|---|---|
| Mar. 31, 2017 | Dec. 31, 2016 | |
| Income Tax Disclosure [Abstract] | ||
| Liability for unrecognized tax | $ 4.9 | $ 4.6 | 
| Unrecognized tax favorable impact on effective tax rate | 4.7 | |
| Accrued interest and penalties applied to uncertain tax positions | $ 2.0 | $ 1.9 | 
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- References No definition available. 
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- Definition Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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