Income Taxes - Deferred Tax Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Liabilities:
Lease Financing	$ 9.0	$ 36.9
Software Development	268.1	249.4
Accumulated Depreciation	99.7	99.8
Compensation and Benefits	31.0	8.3
State Taxes, net	67.4	66.4
Other Liabilities	372.6	206.7
Gross Deferred Tax Liabilities	847.8	667.5
Deferred Tax Assets:
Allowance for Credit Losses	54.5	26.1
Other Assets	139.8	147.0
Gross Deferred Tax Assets	194.3	173.1
Valuation Reserve	(55.2)	(29.8)
Deferred Tax Assets, net of Valuation Reserve	139.1	143.3
Net Deferred Tax Liabilities	$ 708.7	$ 524.2