SCHEDULE IV - MORTGAGE LOANS ON REAL ESTATE - Reconciliation of Loans on Real Estate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of year	$ 153,829	$ 276,163	$ 147,188
Additions	3,805	11,371	171,794
Repayments	(26,000)	(32,000)	(42,819)
Conversion to real estate through receipt of deed	(22,021)	(101,705)
Balance at end of year	$ 109,613	$ 153,829	$ 276,163