ACQUISITION AND DISPOSITION OF PROPERTIES, DISCONTINUED OPERATIONS AND PROPERTIES HELD FOR SALE Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
BALANCE SHEETS
Net real estate					$ 17,991					$ 17,991
Rents receivable, net					565					565
Deferred charges, net					38					38
Prepaid expenses and other assets					1,840					1,840
Total assets of discontinued operations	56,073				20,434				56,073	20,434
LIABILITIES
Accounts payable and accrued expenses					1,473					1,473
Other liabilities					1,034					1,034
Total liabilities of discontinued operations	25,500				2,507				25,500	2,507
STATEMENTS OF INCOME
Total revenues									0	20,920	56,902
Total expenses									0	14,102	44,895
Operating income									0	6,818	12,007
Impairment of assets									0	(6,683)	0
Loss on debt extinguishment									0	(800)	(2,541)
Gain on disposition of properties									1,222	18,802	71,203
Income from discontinued operations									1,222	18,137	80,669
Income from discontinued operations attributable to noncontrolling interests									(1,023)	(12,048)	(64,582)
Income from discontinued operations attributable to Common Shareholders	$ 100	$ 0	$ 99	$ 0	$ 4,675	$ 591	$ 790	$ 33	$ 199	$ 6,089	$ 16,087