Notes Receivable and Allowance for Losses Past Due Balances Of Mezzanine And Other Notes Receivable (Details) (Notes Receivable [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable 30-89 days Past Due	$ 162	$ 619
Financing Receivable >90 days Past Due	9,676	9,676
Financing Receivable Total Past Due	9,838	10,295
Financing Receivable, Current	34,846	33,538
Total Receivables	44,684	43,833
Senior Notes [Member]
Financing Receivable 30-89 days Past Due	0	0
Financing Receivable >90 days Past Due	0	0
Financing Receivable Total Past Due	0	0
Financing Receivable, Current	27,842	27,549
Total Receivables	27,842	27,549
Senior Subordinated Notes [Member]
Financing Receivable 30-89 days Past Due	162	619
Financing Receivable >90 days Past Due	9,629	9,629
Financing Receivable Total Past Due	9,791	10,248
Financing Receivable, Current	5,229	4,771
Total Receivables	15,020	15,019
Unsecured Notes [Member]
Financing Receivable 30-89 days Past Due	0	0
Financing Receivable >90 days Past Due	47	47
Financing Receivable Total Past Due	47	47
Financing Receivable, Current	1,775	1,218
Total Receivables	$ 1,822	$ 1,265