Notes Receivable And Allowance For Losses Summary Of Activity Related To Allowance For Losses (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for losses on non-impaired loans	$ 10,550		$ 9,228
Forgivable Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for losses on non-impaired loans	1,623		795		775
Provisions	1,144		269
Recoveries	(33)		(3)
Write-offs	(213)		(160)
Other	(70)	[1]	(86)	[1]
Mezzanine & Other Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for losses on non-impaired loans	8,927		8,433		9,251
Provisions	591		713
Recoveries	(97)		(1,157)
Write-offs	0		(374)
Other	$ 0	[1]	$ 0	[1]

[1] Consists of default rate assumption changes