Income Taxes (Narrative) (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]
Company's effective tax rate	22.50%	17.60%	22.30%	19.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 1.9		$ 0.2
Reasonable possible increase in unrecognized tax benefits during the next twelve months	6.6		6.6
Increase In Unrecognized Tax Benefits That Would Impact Effective Tax Rate	2.2		0.3
Unrecognized Tax Benefits, Interest on Income Taxes Expense	(0.6)		0.7
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 7.9		$ 7.9		$ 7.2