Notes Receivable and Allowance for Losses Summary Of Activity Related To Allowance For Losses (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 7,430
Ending balance	8,724
Forgivable Notes Receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	5,013
Provisions	1,936
Recoveries	(172)
Write-offs	(11)
Other	(459)
Ending balance	6,307
Mezzanine & Other Notes Receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	2,417
Provisions	0
Recoveries	0
Write-offs	0
Other	0
Ending balance	$ 2,417