Other Operating Expense - (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income and Expenses [Abstract]
Business Promotion	$ 104.2	$ 98.3	$ 95.4
FDIC Insurance Premiums	9.9	27.4	34.7
Staff Related	42.8	33.6	42.8
Other Intangibles Amortization	16.6	17.4	11.4
Other Expenses	156.3	153.9	147.3
Total Other Operating Expense	$ 329.8	$ 330.6	$ 331.6