EQUITY (Details) (USD $)	0 Months Ended									12 Months Ended			3 Months Ended	12 Months Ended						0 Months Ended	12 Months Ended
	Oct. 23, 2013	Jul. 31, 2013	May 01, 2013	Mar. 21, 2013	Jan. 07, 2013	Oct. 29, 2012	Aug. 01, 2012	Apr. 24, 2012	Feb. 29, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 At-the-Market Offering, Sales Agents	Dec. 31, 2013 Ordinary Dividends	Dec. 31, 2012 Ordinary Dividends	Dec. 31, 2011 Ordinary Dividends	Dec. 31, 2013 Return of Capital	Dec. 31, 2012 Return of Capital	Dec. 31, 2011 Return of Capital	Jan. 23, 2014 Subsequent Event Dividend Declared	Dec. 31, 2013 Restricted Stock Units (RSUs)	Dec. 31, 2012 Restricted Stock Units (RSUs)	Dec. 31, 2013 Stock Options	Dec. 31, 2012 Stock Options
Equity
Preferred stock, shares issued				5,800,000						5,750,000	0
Stock-based compensation, issued during period (in shares)																					239,088	165,857	33,935	41,640
Common stock dividends, declared (in dollars per share)	$ 0.34	$ 0.34	$ 0.34		$ 0.34	$ 0.33	$ 0.33	$ 0.33	$ 0.33	$ 1.36	$ 1.32	$ 0.96								$ 0.36
Common dividends, paid										$ 1.36	$ 1.32	$ 0.96		$ 0.4672	$ 0.7992	$ 0.7833	$ 0.8928	$ 0.5208	$ 0.1767
Preferred Stock, Dividend Rate, Percentage										7.125%
Preferred Stock, Redemption Price Per Share				$ 25.00
Issuance of preferred stock				138,300,000						138,249,000	0	0
Convertible Preferred Stock, Terms of Conversion										1.7864
Common Stock, At The Market Stock Offering, Max Possible Gross Proceeds										100,000,000
Common Stock, At the Market Stock Offering, Sales Commision										2.00%
Number of shares of common stock sold under ATM Program													1,400,000
Average price per share of common stock sold under ATM Program													$ 27.01
Gross proceeds from issuance of common stock, ATM Program										34,517,000	53,000	163,242,000	38,300,000
Stock issuance costs, commissions, ATM Program													700,000
Amount available under ATM Program													$ 61,700,000