Income Taxes - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
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| Income Tax Disclosure [Abstract] | |||||
| Provision for income taxes, rate | 28.50% | 39.30% | 27.20% | 39.00% | |
| Tax computed at federal rate, percentage | 21.00% | 35.00% | 21.00% | 35.00% | 35.00% |
| Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense | $ 11.6 | ||||
| X | ||||||||||
- Definition Amount of provisional charge recorded in income tax expense (benefit) due to the revaluation of deferred tax assets, net as a result of the enactment of the Tax Cuts and Jobs Act of 2017 changing the U.S. corporate income tax rate to 21% from 35% starting in 2018. No definition available.
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| X | ||||||||||
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- References No definition available.
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