Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Company's effective tax rate	20.90%	21.80%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 0.1
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	0.1
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0.1
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	7.6		$ 7.5
Reasonable possible increase in unrecognized tax benefits during the next twelve months	$ 9.4

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

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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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 accrued 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.

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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.

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Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

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

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