Real Estate Loans Receivable (Details 1) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Summary of loan impairments
Balance of impaired loans at end of period		$ 214,896	$ 317,049
Allowance for loan losses		68,372	6,196
Balance of impaired loans not reserved		146,524	310,853
Average impaired loans for the period		265,973	340,920
Interest recognized on impaired loans	[1]	$ 5,327	$ 8,243

[1] Represents cash interest recognized in the period since loans were identified as impaired.