Notes Payable (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Notes outstanding	$ 59,057	$ 59,030
Weighted Average Interest Rate	6.46%	6.40%
Class A Notes
Notes outstanding	46,156	46,500
Weighted Average Interest Rate	4.01%
Alpha Class Notes
Notes outstanding	3,767	4,400
Weighted Average Interest Rate	5.66%
Special Offering
Notes outstanding	8,866
Weighted Average Interest Rate	4.53%
Special Subordinated Note
Notes outstanding	6
Weighted Average Interest Rate	5.45%
Secured Note
Notes outstanding	55
Weighted Average Interest Rate	2.49%
International Offering
Notes outstanding	207
Weighted Average Interest Rate	4.27%
Notes Payable
Notes outstanding	$ 59,057
Weighted Average Interest Rate	4.20%