Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Allowance for credit losses	$ 100.4	$ 118.2
Stock-based compensation	14.3	18.3
Deferred state net operating loss	8.1	6.5
Other, net	4.0	11.6
Total deferred tax assets	126.8	154.6
Deferred Tax Assets, Valuation Allowance	(5.5)	0.0
Deferred Tax Assets, Net of Valuation Allowance	121.3	154.6
Valuation of Loans receivable	300.4	417.8
Deferred Loan origination costs	1.5	2.5
Other, net	6.8	7.4
Total deferred tax liabilities	308.7	427.7
Deferred income taxes, net	$ 187.4	$ 273.1