Debt (Schedule Of Outstanding Debt Amount) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Balance outstanding	$ 43.5		$ 43.9
Balance outstanding	853.0		599.3
Balance outstanding	350.3		350.4
Restricted cash and cash equivalents pledged as collateral	92.4		104.7
Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Balance outstanding	43.5		43.9
Amount available for borrowing	191.5	[1]	161.1	[1]
Interest rate	2.08%		2.55%
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Balance outstanding	81.3		163.2
Amount available for borrowing	243.7	[1]	161.8	[1]
Loans pledged as collateral	105.2		242.1
Restricted cash and cash equivalents pledged as collateral	3.0		6.1
Interest rate	2.22%		2.99%
Warehouse Facility III [Member]
Debt Instrument [Line Items]
Balance outstanding			70.0
Amount available for borrowing	75.0	[1]	5.0	[1]
Loans pledged as collateral			91.6
Restricted cash and cash equivalents pledged as collateral	0.4		3.3
Interest rate	1.82%		1.89%
Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Balance outstanding	37.6		37.5
Amount available for borrowing	37.4	[1]	37.5	[1]
Loans pledged as collateral	47.7		62.3
Restricted cash and cash equivalents pledged as collateral	2.5		2.2
Interest rate	2.96%		3.05%
Term ABS 2009-1 [Member]
Debt Instrument [Line Items]
Balance outstanding			27.6
Loans pledged as collateral			105.2
Restricted cash and cash equivalents pledged as collateral			13.5
Interest rate			5.68%
Term ABS 2010-1 [Member]
Debt Instrument [Line Items]
Balance outstanding	80.3		100.5
Loans pledged as collateral	111.6		125.5
Restricted cash and cash equivalents pledged as collateral	12.5		14.1
Interest rate	2.44%		2.36%
Term ABS 2011-1 [Member]
Debt Instrument [Line Items]
Balance outstanding	200.5		200.5
Loans pledged as collateral	243.8		248.2
Restricted cash and cash equivalents pledged as collateral	23.5		23.3
Interest rate	2.90%		2.90%
Term ABS 2012-1 [Member]
Debt Instrument [Line Items]
Balance outstanding	201.3
Loans pledged as collateral	244.7
Restricted cash and cash equivalents pledged as collateral	22.3
Interest rate	2.38%
Term ABS 2012-2 [Member]
Debt Instrument [Line Items]
Balance outstanding	252.0
Loans pledged as collateral	311.9
Restricted cash and cash equivalents pledged as collateral	26.0
Interest rate	1.63%
Senior Notes [Member]
Debt Instrument [Line Items]
Balance outstanding	350.3	[2]	350.4	[2]
Interest rate	9.13%		9.13%
Unamortized debt premium net	$ 0.3		$ 0.4

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

[2] As of December 31, 2012 and 2011, the outstanding balance presented for the Senior Notes includes a net unamortized debt premium of $0.3 million and $0.4 million, respectively.