Loans Receivable Held for Investment - Aging of Recorded Investment in Past Due Loans by Loan Type (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Past due receivable
Total Past Due	$ 18	$ 35
Current	401,011	358,450
Gross loans receivable after deferred loan costs and premiums	401,029	358,485
30-59 Days Past Due
Past due receivable
Total Past Due	18	35
Single family
Past due receivable
Total Past Due	18	35
Current	73,094	92,142
Gross loans receivable after deferred loan costs and premiums	73,112	92,177
Single family | 30-59 Days Past Due
Past due receivable
Total Past Due	18	35
Multi-family
Past due receivable
Current	289,043	233,309
Gross loans receivable after deferred loan costs and premiums	289,043	233,309
Commercial real estate
Past due receivable
Current	14,818	5,800
Gross loans receivable after deferred loan costs and premiums	14,818	5,800
Church
Past due receivable
Current	20,648	25,096
Gross loans receivable after deferred loan costs and premiums	20,648	25,096
Construction
Past due receivable
Current	3,125	1,872
Gross loans receivable after deferred loan costs and premiums	3,125	1,872
Commercial - other
Past due receivable
Current	262	226
Gross loans receivable after deferred loan costs and premiums	262	226
Consumer
Past due receivable
Current	21	5
Gross loans receivable after deferred loan costs and premiums	$ 21	$ 5