STOCKHOLDERS' EQUITY (Details) (USD $)	1 Months Ended		12 Months Ended								12 Months Ended	1 Months Ended		12 Months Ended
	Jan. 31, 2013	Oct. 30, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2013 Cumulative Redeemable Preferred Stock, Series E [Member]	May 31, 2013 Cumulative Redeemable Preferred Stock, Series E [Member]	Dec. 31, 2013 Series A And Series B Preferred Stock [Member]	Jun. 30, 2013 Series A Perpetual Preferred Shares [Member]	Jun. 30, 2013 Series B Perpetual Preferred Share [Member]	Dec. 31, 2012 Series B Perpetual Preferred Share [Member]	Dec. 31, 2011 Series B Perpetual Preferred Share [Member]	Dec. 31, 2012 Continuous Offering Program [Member]	Dec. 31, 2011 Continuous Offering Program [Member]	Dec. 31, 2013 Continuous Offering Program [Member] Cumulative Redeemable Preferred Stock, Series E [Member]	Dec. 31, 2013 Directors And Employees [Member]	Dec. 31, 2012 Directors And Employees [Member]	Dec. 31, 2011 Directors And Employees [Member]
Stockholders' Equity [Line Items]
Redeemable preferred stock, shares issued (in shares)										6,800,000
Redeemable preferred stock, face value										$ 170,000,000
Preferred stock dividend rate (in hundredths)									7.50%
Redeemable preferred stock, liquidation preference per share (in dollars per share)										$ 25.00
Preferred stock, redemption price per share (in dollars per share)										$ 25.00
Proceeds from issuance of redeemable preferred stock									164,300,000									1,400,000
Cash on hand paid to redeem preferred stock									42,700,000
Preferred stock, redemption date											Jun. 13, 2013
Preferred stock, redemption shares (in shares)												77,000	16,500,000
Preferred stock, shares outstanding (in shares)												109,000	32,000
Common stock, shares, issued on conversion of preferred stock (in shares)												181,000	20,000
Cash used for redemption of preferred stock											207,000,000
Redemption preference premiums paid			19,924,000	[1]	0	[1]	0	[1]			19,900,000
Reduction in income per share (in dollars per share)											$ 0.21
Proceeds from issuance of common stock			0		142,035,000		231,674,000									142,000,000	231,700,000
Additional shares issued (in shares)														309,000	365,000	10,500,000	17,800,000	61,000
Proceeds from issuance of preferred equity capital			165,756,000		4,479,000		5,206,000							4,500,000	5,200,000
Common stock repurchase program		100,000,000
Shares repurchased (in shares)	638,000				3,000,000
Average cost per share (in dollars per share)	$ 11.43				$ 11.80
Value of stock repurchased	7,300,000				35,100,000
Additions to common equity capital related to equity-based awards																			$ 1,800,000	$ 4,400,000	$ 3,200,000

[1] The Series A and Series B preferred shares were redeemed on June 13, 2013 (See NOTE 11).