Derivative And Hedging Instruments (Schedule Of Terms Of Interest Rate Cap Agreements) (Details) - USD ($)		Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Debt financing amount		$ 2,622,100,000	$ 2,086,300,000
Interest rate swap agreements outstanding		100,000
Warehouse Facility II [Member]
Derivative [Line Items]
Debt financing amount	[1],[2]	400,000,000
Warehouse Facility II [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Debt financing amount		400,000,000	400,000,000
Notional value		$ 325,000,000	$ 325,000,000
Cap Interest Rate	[3]	5.50%	5.50%
Warehouse Facility IV [Member]
Derivative [Line Items]
Debt financing amount	[1],[2]	$ 75,000,000
Warehouse Facility IV [Member] | Original 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Notional value		$ 18,800,000
Cap Interest Rate	[3]	5.50%
Warehouse Facility IV [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Debt financing amount		$ 75,000,000	$ 75,000,000
Notional value		75,000,000	$ 75,000,000
Cap Interest Rate	[3]		5.50%
Warehouse Facility IV Member Starting March 2014 [Member] | Additional 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Notional value		$ 56,200,000
Cap Interest Rate	[3]	5.50%
Warehouse Facility V [Member]
Derivative [Line Items]
Debt financing amount	[1],[2]	$ 100,000,000
Warehouse Facility V [Member] | 5.50% Cap Interest Rate [Member]
Derivative [Line Items]
Debt financing amount		100,000,000	$ 100,000,000
Notional value		$ 75,000,000	$ 75,000,000
Cap Interest Rate	[3]	5.50%	5.50%
Term ABS 2016-1 [Member]
Derivative [Line Items]
Debt financing amount	[1]	$ 385,000,000
Term ABS 2016-1 [Member] | 5.00% Cap Interest Rate [Member]
Derivative [Line Items]
Debt financing amount		385,000,000
Notional value		$ 385,000,000
Cap Interest Rate	[3]	5.00%

[1] Financing made available only to a specified subsidiary of the Company.

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

[3] Rate excludes the spread over the LIBOR rate.