CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Rental and other property revenues (including $726, $701 and $670 for the year ended 2015, 2014 and 2013, respectively, from related parties)	$ 102,220	$ 75,858	$ 77,351
Property operating expenses (including $740, $606 and $661 for the year ended 2015, 2014 and 2013, respectively, from related parties)	52,257	39,484	36,669
General and administrative (including $3,105, $2,802 and $2,765 for the year ended 2015, 2014 and 2013, respectively, from related parties)	5,508	7,163	6,308
Interest income (including $10,071, $11,469 and $13,823 for the year ended 2015, 2014 and 2013, respectively, from related parties)	10,687	12,194	13,790
Mortgage and loan interest (including $0, $31, and $1,761 for the year ended 2015, 2014 and 2013, respectively, from related parties)	(41,586)	(30,877)	(32,276)
Related Party [Member]
Rental and other property revenues (including $726, $701 and $670 for the year ended 2015, 2014 and 2013, respectively, from related parties)	726	701	670
Property operating expenses (including $740, $606 and $661 for the year ended 2015, 2014 and 2013, respectively, from related parties)	740	606	661
General and administrative (including $3,105, $2,802 and $2,765 for the year ended 2015, 2014 and 2013, respectively, from related parties)	3,105	2,802	2,765
Interest income (including $10,071, $11,469 and $13,823 for the year ended 2015, 2014 and 2013, respectively, from related parties)	10,071	11,469	13,823
Mortgage and loan interest (including $0, $31, and $1,761 for the year ended 2015, 2014 and 2013, respectively, from related parties)	$ 0	$ 31	$ 1,761