Deferred Tax Liabilities and Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Liabilities:
Lease Financing	$ 148.7	$ 272.6	$ 388.6
Software Development	352.0	339.9	316.1
Accumulated Depreciation	26.0	20.6	24.1
Compensation and Benefits	50.2	70.7	63.5
State Taxes, net	33.3	48.8	62.3
Other Liabilities	243.1	169.1	157.5
Gross Deferred Tax Liabilities	853.3	921.7	1,012.1
Deferred Tax Assets:
Allowance for Credit Losses	67.2	81.7	103.5
Other Assets	233.8	185.0	126.7
Gross Deferred Tax Assets	301.0	266.7	230.2
Valuation Reserve	(0.9)	(1.6)	(3.9)
Deferred Tax Assets, net of Valuation Reserve	300.1	265.1	226.3
Net Deferred Tax Liabilities	$ 553.2	$ 656.6	$ 785.8