Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred Tax Liabilities:
Lease Financing	$ 0.0	$ 7.0
Software Development	354.7	271.8
Depreciation and Amortization	122.6	181.3
Unrealized Gains on Securities, net	0.0	82.8
Compensation and Benefits	5.2	65.6
State Taxes, net	58.3	76.3
Other Liabilities	42.1	23.3
Gross Deferred Tax Liabilities	582.9	708.1
Deferred Tax Assets:
Allowance for Credit Losses	41.8	38.6
Unrealized Losses on Securities, net	427.3	0.0
Tax Credit and Loss Carryforwards	95.3	68.2
Other Assets	143.7	85.4
Gross Deferred Tax Assets	708.1	192.2
Valuation Reserve	(95.3)	(68.2)
Deferred Tax Assets, net of Valuation Reserve	612.8	124.0
Net Deferred Tax Assets (Liabilities)	$ 29.9
Net Deferred Tax Assets (Liabilities)		$ (584.1)