Schedule IV - Real Estate Mortgage Loans (Mortgage Loan Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning Balance	$ 784,821	$ 747,456	$ 335,656
New Loans	140,000	88,648	451,269
Construction Draws	13,403	53,708	0
Total additions	153,403	142,356	451,269
Principal Repayments	(303,255)	(99,467)	(21,159)
Conversions to Real Property	0	0	(18,310)
Sales and Syndications	0	0	0
Spin Off	0	(5,524)	0
Total deductions	(303,255)	(104,991)	(39,469)
Ending Balance	$ 634,969	$ 784,821	$ 747,456