SCHEDULE IV - MORTGAGE LOANS ON REAL ESTATE - Mortgage Loan Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement in Mortgage Loans on Real Estate
Balance, beginning of period	$ 68,079	$ 83,248	$ 81,056
Additions during period:
New loans	53,524	39,592	74,234
Other - deferral for collection of commitment fees, net of costs	382	802	1,587
Other - accretion of loan fees and discounts	933	1,303	1,026
Deductions during period:
Collections of principal	(11,580)	(13,886)	(16,468)
Foreclosures	(174)	(241)	0
Cost of mortgages sold, net	(27,609)	(42,663)	(57,947)
Other - reclassification from secured borrowings	0	0	0
Other - bad debt expense	(420)	(76)	(240)
Balance, end of period	$ 83,135	$ 68,079	$ 83,248