Debt (Narrative) (Details) (USD $)	3 Months Ended				6 Months Ended	3 Months Ended	6 Months Ended						3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Warehouse Facilities [Member]	Jun. 30, 2012 Revolving Secured Line Of Credit [Member]	Mar. 31, 2012 Revolving Secured Line Of Credit [Member]	Jun. 30, 2012 Revolving Secured Line Of Credit [Member]	Mar. 31, 2012 Warehouse Facility II [Member]	Jun. 30, 2012 Warehouse Facility II [Member]		Jun. 30, 2012 Warehouse Facility III [Member]		Jun. 30, 2012 Warehouse Facility IV [Member]		Jun. 30, 2012 Senior Notes [Member]	Jun. 30, 2012 Senior Notes [Member]	Mar. 03, 2011 Senior Notes [Member]	Mar. 31, 2011 $100.0 Million Senior Notes [Member]	Jun. 30, 2012 $100.0 Million Senior Notes [Member]	Mar. 03, 2011 $100.0 Million Senior Notes [Member]	Mar. 31, 2010 $250.0 Million Senior Notes [Member]	Jun. 30, 2012 $250.0 Million Senior Notes [Member]	Feb. 01, 2010 $250.0 Million Senior Notes [Member]	Jun. 30, 2012 LIBOR [Member] Revolving Secured Line Of Credit [Member]	Mar. 31, 2012 LIBOR [Member] Revolving Secured Line Of Credit [Member]	Jun. 30, 2012 LIBOR [Member] Warehouse Facility II [Member]		Jun. 30, 2012 LIBOR [Member] Warehouse Facility III [Member]		Jun. 30, 2012 LIBOR [Member] Warehouse Facility IV [Member]		Jun. 30, 2012 Prime Rate [Member] Revolving Secured Line Of Credit [Member]	Mar. 31, 2012 Prime Rate [Member] Revolving Secured Line Of Credit [Member]	Jun. 30, 2012 Commercial Paper Rate [Member] Warehouse Facility II [Member]		Jun. 30, 2012 6.75% Cap Interest Rate [Member] Warehouse Facility II [Member]		Dec. 31, 2011 6.75% Cap Interest Rate [Member] Warehouse Facility II [Member]		Jun. 30, 2012 6.75% Cap Interest Rate [Member] Warehouse Facility III [Member]		Dec. 31, 2011 6.75% Cap Interest Rate [Member] Warehouse Facility III [Member]		Jun. 30, 2012 5.00% Cap Interest Rate [Member] Warehouse Facility III [Member]		Jun. 30, 2012 5.5% Cap Interest Rate [Member] Warehouse Facility IV [Member]		Dec. 31, 2011 5.5% Cap Interest Rate [Member] Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Line of credit facility			$ 235,000,000	$ 205.0	$ 235,000,000
Maturity Date				Jun. 22, 2014	Jun. 22, 2015
Debt financing amount		475,000,000					325,000,000	[1]	75,000,000	[1]	75,000,000	[1]	350,000,000	350,000,000	100,000,000			100,000,000			250,000,000													325,000,000		325,000,000		75,000,000		75,000,000		75,000,000		75,000,000		75,000,000
Percentage of net book value of loans		80.00%	80.00%
Maximum hedging reserve	1,000,000
Cap Interest Rate							6.75%		6.75%		5.50%																							6.75%	[2],[3]	6.75%	[2]	6.75%	[2],[3]	6.75%	[2]	5.00%	[2],[3]	5.50%	[2],[3]	5.50%	[2]
Percentage of debt covered by interest rate caps																																						50.00%				25.00%
Percentage of collections on contributed loans	6.00%
Number of wholly owned subsidiaries acquiring financing	4
Senior notes stated interest rate													9.125%	9.125%
Debt maturity date						Sep. 10, 2013	Jun. 17, 2014	[1],[4]	Sep. 10, 2015	[1],[5]	Feb. 19, 2014	[1],[4]	Feb. 01, 2017	Feb. 01, 2017
Close date, secured financings							Jun. 17, 2011	[1]	Jun. 29, 2012	[1]	Aug. 19, 2011	[1]					Mar. 03, 2011			Feb. 01, 2010
Percentage of price for senior notes issued																		106.00%			97.495%
Gross proceeds																106,000,000			243,700,000
Senior notes yield to maturity																		7.83%			9.625%
Debt covenants	$ 1
Basis spread on variable rate																						1.875%	2.25%	3.75%	[1],[6],[7]	1.60%	[1],[7]	2.75%	[1],[7]	0.875%	1.25%	2.75%	[1],[6],[7]

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

[2] Rate excludes the spread over the LIBOR rate or the commercial paper rate, as applicable.The notional amount increases to $56.3 million in September 2013 when the original Warehouse Facility III interest rate cap for $37.5 million ends..

[3] Rate excludes the spread over the LIBOR rate or the commercial paper rate, as applicable.

[4] Represents the revolving maturity date.  The outstanding balance will amortize after the maturity date based on the cash flows of the pledged assets.

[5] Represents the revolving maturity date.  The outstanding balance will amortize after the revolving maturity date and any amounts remaining on September 10, 2017 will be due.

[6] The LIBOR rate is used if funding is not available from the commercial paper market.

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