Derivative And Hedging Instruments (Schedule Of Terms Of Interest Rate Cap Agreements) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018
Derivative [Line Items]
Document Period End Date		Dec. 31, 2019
Interest rate swap fair value		$ 0.1		$ 0.0
Warehouse Facility II [Member]
Derivative [Line Items]
Debt financing amount		400.0	[1]	400.0
Warehouse Facility II [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 205.0		$ 205.0
Cap Interest Rate	[2]	5.50%		5.50%
Warehouse Facility IV [Member]
Derivative [Line Items]
Debt financing amount		$ 300.0	[1]	$ 250.0
Derivative, Notional Amount		300.0		250.0
Warehouse Facility IV [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 25.0
Cap Interest Rate	[2]			5.50%
Warehouse Facility IV [Member] | 6.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 100.0		$ 75.0
Cap Interest Rate	[2]	6.50%		6.50%
Warehouse Facility IV [Member] | Additional 6.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 150.0		$ 150.0
Cap Interest Rate	[2]	6.50%		6.50%
Warehouse Facility IV [Member] | Second Additional 6.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 50.0
Cap Interest Rate	[2]	6.50%
Warehouse Facility V [Member]
Derivative [Line Items]
Debt financing amount		$ 100.0	[1]	$ 100.0
Warehouse Facility V [Member] | 6.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 75.0		$ 75.0
Cap Interest Rate	[2]	6.50%		6.50%
Term ABS 2016-1 [Member]
Derivative [Line Items]
Debt financing amount				$ 125.3
Term ABS 2016-1 [Member] | 5.00% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 64.2
Cap Interest Rate	[2]			5.00%
Warehouse Facility VII [Member]
Derivative [Line Items]
Debt financing amount		$ 150.0	[1]	$ 150.0
Warehouse Facility VII [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 143.8		$ 150.0
Cap Interest Rate	[2]	5.50%		5.50%
Warehouse Facility VIII [Member]
Derivative [Line Items]
Debt financing amount	[1]	$ 200.0
Warehouse Facility VIII [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 200.0
Cap Interest Rate	[2]	5.50%

[1] Interest rate cap agreements are in place to limit the exposure to increasing interest rates.

[2] Rate excludes the spread over the corresponding LIBOR or commercial paper rate.