CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Rental and other property revenues	$ 120,955	$ 125,233	$ 118,471
Property operating expenses	59,420	63,056	61,918
General and administrative	11,359	6,269	5,476
Interest income	15,793	13,862	14,670
Mortgage and loan interest	58,872	59,944	53,088
Related Parties [Member]
Rental and other property revenues	767	839	708
Property operating expenses	943	929	865
General and administrative	4,578	3,120	3,574
Interest income	13,132	11,485	13,348
Mortgage and loan interest	$ 423	$ 1,174	$ 568