Borrowings-Future Payments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Scheduled principal payment requirements on borrowings
July 1 to December 31, 2014	$ 11,685
Years Ending December 31:
2015	0
2016	16,200
2017	51,000
2018	106,598
Thereafter	597,996
Total	783,479	638,182
Securitization Bonds Payable
Scheduled principal payment requirements on borrowings
July 1 to December 31, 2014	0
Years Ending December 31:
2015	0
2016	0
2017	0
2018	0
Thereafter	482,593
Total	482,593	507,359
Mortgage notes payable
Scheduled principal payment requirements on borrowings
July 1 to December 31, 2014	0
Years Ending December 31:
2015	0
2016	16,200
2017	0
2018	0
Thereafter	115,403
Total	131,603	102,500
Credit facilities
Scheduled principal payment requirements on borrowings
July 1 to December 31, 2014	11,685
Years Ending December 31:
2015	0
2016	0
2017	51,000
2018	106,598
Thereafter	0
Total	$ 169,283	$ 28,323