Loans Receivable (Summary Of Information Related To New Consumer Loan Assignments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual net cash flows at the time of assignment	[1]	$ 6,763.9	$ 6,438.1	$ 5,105.3
Expected net cash flows at the time of assignment	[2]	5,305.0	5,074.4	4,054.0
Fair value at the time of assignment	[3]	3,772.2	3,595.8	2,873.1
Dealer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual net cash flows at the time of assignment	[1]	3,810.6	3,827.4	3,131.6
Expected net cash flows at the time of assignment	[2]	3,396.1	3,405.0	2,771.3
Fair value at the time of assignment	[3]	2,424.5	2,414.8	1,968.3
Purchased Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractual net cash flows at the time of assignment	[1]	2,953.3	2,610.7	1,973.7
Expected net cash flows at the time of assignment	[2]	1,908.9	1,669.4	1,282.7
Fair value at the time of assignment	[3]	$ 1,347.7	$ 1,181.0	$ 904.8

[1] The Dealer Loans amount represents the repayments that we were contractually owed at the time of assignment on Consumer Loans assigned under our Portfolio Program, less the related Dealer Holdback payments that we would be required to make if we collected all of the contractual repayments.  The Purchased Loans amount represents the repayments that we were contractually owed at the time of assignment on Consumer Loans assigned under our Purchase Program

[2] The Dealer Loans amount represents the repayments that we expected to collect at the time of assignment on Consumer Loans assigned under our Portfolio Program, less the related Dealer Holdback payments that we expected to make.  The Purchased Loans amount represents the repayments that we expected to collect at the time of assignment on Consumer Loans assigned under our Purchase Program

[3] The Dealer Loans amount represents advances paid to Dealers on Consumer Loans assigned under our Portfolio Program.  The Purchased Loans amount represents one-time payments made to Dealers to purchase Consumer Loans assigned under our Purchase Program