Collateralized Receivables and Transfers of Financial Assets, Narrative (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes and other receivables, net	$ 110,499		$ 81,179
Secured debt	2,832,819		2,819,567
Interest income and expense, net	3,300	$ 3,400
Collateralized Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Allowance	$ 800		$ 607
Receivable With Imputed Interest, Term	15 years 7 months 6 days		15 years 8 months 12 days
Receivable with Imputed Interest, Effective Yield (Interest Rate)	10.00%		1000.00%
Carrying Value [Member] | Secured Debt [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Secured debt	$ 139,496		$ 144,477
Carrying Value [Member] | Collateralized Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes and other receivables, net	$ 138,700		$ 143,870