SHAREHOLDERS' EQUITY AND PARTNERS' CAPITAL (Preferred Stock and Preferred Units) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shareholders Equity [Line Items]
Preferred stock, shares authorized (in shares)	15,000,000
Preferred stock, par value (in dollars per share)	$ 0.01
Issuance of shares of stock (in shares)	348,809	335,417	278,093
Series E preferred stock
Shareholders Equity [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Issuance of shares of stock (in shares)	6,900,000	6,900,000
Preferred stock, dividend rate	6.625%	6.625%
Preferred stock, liquidation preference per share (in dollars per share)	$ 250.00
Depositary shares, liquidation preference (in dollars per share)	25
Dividends in arrears per share (in dollars per share)	16.5625
Dividends in arrears per depositary share (in dollars per share)	1.65625
Redemption price per share (in dollars per share)	250
7.375% Series D Cumulative Redeemable Preferred Stock
Shareholders Equity [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, dividend rate	7.375%	7.375%
Preferred stock, liquidation preference per share (in dollars per share)	$ 250
Depositary shares, liquidation preference (in dollars per share)	25
Dividends in arrears per share (in dollars per share)	18.4375
Dividends in arrears per depositary share (in dollars per share)	$ 1.84375
Depositary shares outstanding (in shares)	18,150,000	18,150,000