Debt (Schedule Of Outstanding Debt Amount) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Debt Instrument [Line Items]
Balance outstanding	$ 115.9		$ 102.8
Balance outstanding	1,138.6		935.6
Restricted cash and cash equivalents pledged as collateral	146.6		111.3
Balance outstanding	300.0		350.2
Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Balance outstanding	115.9		102.8
Amount available for borrowing	119.1	[1]	132.2	[1]
Interest rate	2.03%		2.04%
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Balance outstanding	162.6		0
Amount available for borrowing	162.4	[1]	325.0	[1]
Loans pledged as collateral	238.0		0
Restricted cash and cash equivalents pledged as collateral	3.8		1.2
Interest rate	2.15%		2.17%
Warehouse Facility III [Member]
Debt Instrument [Line Items]
Balance outstanding	69.1
Amount available for borrowing	5.9	[1]	75.0	[1]
Loans pledged as collateral	104.2
Restricted cash and cash equivalents pledged as collateral	1.9		0.3
Interest rate	1.76%		1.77%
Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Balance outstanding	25.0
Amount available for borrowing	50.0	[1]	75.0	[1]
Loans pledged as collateral	42.8
Restricted cash and cash equivalents pledged as collateral	1.5		0.2
Interest rate	2.15%		2.17%
Term ABS 2011-1 [Member]
Debt Instrument [Line Items]
Balance outstanding	90.5		144.2
Loans pledged as collateral	186.4		215.3
Restricted cash and cash equivalents pledged as collateral	26.7		23.2
Interest rate	3.25%		3.01%
Term ABS 2012-1 [Member]
Debt Instrument [Line Items]
Balance outstanding	201.3		201.3
Loans pledged as collateral	238.1		240.4
Restricted cash and cash equivalents pledged as collateral	30.4		23.5
Interest rate	2.38%		2.38%
Term ABS 2012-2 [Member]
Debt Instrument [Line Items]
Balance outstanding	252.0		252.0
Loans pledged as collateral	298.1		303.8
Restricted cash and cash equivalents pledged as collateral	35.9		27.7
Interest rate	1.63%		1.63%
Term ABS 2013-1 [Member]
Debt Instrument [Line Items]
Balance outstanding	140.3		140.3
Loans pledged as collateral	188.7		184.3
Restricted cash and cash equivalents pledged as collateral	19.7		15.3
Interest rate	1.31%		1.31%
Term ABS 2013-2 [Member]
Debt Instrument [Line Items]
Balance outstanding	197.8		197.8
Loans pledged as collateral	249.1		250.5
Restricted cash and cash equivalents pledged as collateral	24.1		18.7
Interest rate	1.67%		1.67%
2017 Senior Notes [Member]
Debt Instrument [Line Items]
Balance outstanding	0	[2]	350.2	[2]
Interest rate	0.00%		9.125%
Unamortized debt premium net			0.2
2021 Senior Notes [Member]
Debt Instrument [Line Items]
Balance outstanding	$ 300.0		$ 0
Interest rate	6.125%		0.00%

[1] Availability may be limited by the amount of assets pledged as collateral

[2] As of December 31, 2013, the outstanding balance presented for the 2017 Senior Notes includes a net unamortized debt premium of $0.2 million, respectively.