Loans Receivable - Internal Ratings for Loans Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 313,326	$ 807,954
Percentage of Loan Portfolio	100.00%
Performing Loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 208,326
Watch List Loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	0
Workout Loans(1)
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	105,000
Real Estate Secured
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 188,418	196,359
Percentage of Loan Portfolio	60.00%
Real Estate Secured | Performing Loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 188,418
Real Estate Secured | Watch List Loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	0
Real Estate Secured | Workout Loans(1)
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	0
Other Secured
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 124,908	$ 611,595
Percentage of Loan Portfolio	40.00%
Other Secured | Performing Loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 19,908
Other Secured | Watch List Loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	0
Other Secured | Workout Loans(1)
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, net	$ 105,000