Fair Value of Financial Instruments (Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment, net	$ 0	$ 0
Total assets	0	0
Fixed-rate debt	0	0
Total fixed-rate debt	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment, net	0	0
Total assets	0	0
Fixed-rate debt	0	0
Total fixed-rate debt	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment, net	1,155,464	932,343
Total assets	1,155,464	932,343
Fixed-rate debt	226,965	293,512
Total fixed-rate debt	226,965	293,512
Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment, net	1,029,117	843,781
Total assets	1,029,117	843,781
Fixed-rate debt	232,972	300,706
Total fixed-rate debt	232,972	300,706
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for investment, net	1,155,464	932,343
Total assets	1,155,464	932,343
Fixed-rate debt	226,965	293,512
Total fixed-rate debt	$ 226,965	$ 293,512