Derivative Financial Instruments (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Derivative financial instruments
Notional	$ 521,848,000		$ 549,622,000
Total loss on termination of derivative	(574,000)	(174,000)
Unrealized gain (loss)	(1,463,000)	11,303,000
Fair Market Value	(71,488,000)		(70,296,000)
Interest Rate Swaps | Hedge accounting has not been applied
Derivative financial instruments
Terminated notional value	35,000,000	55,400,000
Total loss on termination of derivative	(600,000)	(200,000)
Unrealized gain (loss)		0
Interest Rate Swaps | Hedge accounting has not been applied | Maximum
Derivative financial instruments
Unrealized gain (loss)	(100,000)
Interest Rate Swaps | Long-term debt issued by securitization and permanent financing trusts | Hedge accounting has not been applied
Derivative financial instruments
Notional	277,300,000
Floating rate basis	1 month LIBOR
Unrealized gain (loss)	400,000	5,700,000
Number of outstanding derivatives	8
Interest Rate Swaps | Long-term debt issued by securitization and permanent financing trusts | Hedge accounting has not been applied | Minimum
Derivative financial instruments
Fixed interest rate (as a percent)	4.66%
Term of contract	8 years
Interest Rate Swaps | Long-term debt issued by securitization and permanent financing trusts | Hedge accounting has not been applied | Maximum
Derivative financial instruments
Fixed interest rate (as a percent)	5.77%
Term of contract	22 years
Interest Rate Swaps | Borrowings under PSS and PLMT | Hedge accounting has not been applied
Derivative financial instruments
Notional	244,500,000
Floating rate basis	1 month LIBOR
Unrealized gain (loss)	(1,900,000)	5,700,000
Number of outstanding derivatives	162
Interest Rate Swaps | Borrowings under PSS and PLMT | Hedge accounting has not been applied | Minimum
Derivative financial instruments
Fixed interest rate (as a percent)	4.38%
Term of contract	1 month
Interest Rate Swaps | Borrowings under PSS and PLMT | Hedge accounting has not been applied | Maximum
Derivative financial instruments
Fixed interest rate (as a percent)	8.70%
Term of contract	20 years
321 Henderson I | Interest Rate Swaps | 2004-A A-1 | Hedge accounting has not been applied
Derivative financial instruments
Notional	38,207,000		40,734,000
Fair Market Value	(3,523,000)		(3,745,000)
321 Henderson I | Interest Rate Swaps | 2005-1 A-1 | Hedge accounting has not been applied
Derivative financial instruments
Notional	69,861,000		73,269,000
Fair Market Value	(8,212,000)		(8,559,000)
321 Henderson II | Interest Rate Swaps | 2006-1 A-1 | Hedge accounting has not been applied
Derivative financial instruments
Notional	19,320,000		20,976,000
Fair Market Value	(1,939,000)		(2,137,000)
322 Henderson II | Interest Rate Swaps | 2006-2 A-1 | Hedge accounting has not been applied
Derivative financial instruments
Notional	22,433,000		23,620,000
Fair Market Value	(3,058,000)		(3,202,000)
323 Henderson II | Interest Rate Swaps | 2006-3 A-1 | Hedge accounting has not been applied
Derivative financial instruments
Notional	24,534,000		25,902,000
Fair Market Value	(2,860,000)		(3,023,000)
324 Henderson II | Interest Rate Swaps | 2006-4 A-1 | Hedge accounting has not been applied
Derivative financial instruments
Notional	22,620,000		23,842,000
Fair Market Value	(2,491,000)		(2,643,000)
325 Henderson II | Interest Rate Swaps | 2007-1 A-2 | Hedge accounting has not been applied
Derivative financial instruments
Notional	39,364,000		39,364,000
Fair Market Value	(5,373,000)		(5,159,000)
326 Henderson II | Interest Rate Swaps | 2007-2 A-3 | Hedge accounting has not been applied
Derivative financial instruments
Notional	41,004,000		41,544,000
Fair Market Value	(8,318,000)		(8,015,000)
JGW V, LLC | Interest Rate Swaps | Hedge accounting has not been applied
Derivative financial instruments
Notional			10,985,000
Fair Market Value			16,000
PSS | Interest Rate Swaps | Hedge accounting has not been applied | VIE
Derivative financial instruments
Notional	188,599,000		192,444,000
Fair Market Value	(26,877,000)		(25,120,000)
PLMT | Interest Rate Swaps | Hedge accounting has not been applied
Derivative financial instruments
Notional	55,906,000		56,942,000
Fair Market Value	$ (8,837,000)		$ (8,709,000)