Income Taxes (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective tax rate	20.00%	16.20%	30.40%	17.20%
Unrecognized tax benefits	$ 10.3		$ 10.3		$ 9.5
Unrecognized tax benefits if recognized that would affect effective tax rate	10.3		10.3		$ 8.4
Unrecognized tax benefits subject to change within the next 12 months	$ 4.5		$ 4.5

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

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Amount of unrecognized tax benefits.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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