EQUITY (Details) (USD $)	0 Months Ended		3 Months Ended
	Mar. 21, 2013	Jan. 07, 2013	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Equity [Line Items]
Preferred stock, shares issued	5,750,000		5,750,000		0
Common dividends, declared		$ 0.34	$ 0.34	$ 0.33
Stock issuance, Value				$ (370,000)
Shares sold to underwriters (in shares)	800,000
Preferred Stock, Dividend Rate, Percentage			7.125%
Preferred Stock, Redemption Price Per Share	$ 25.00
Proceeds from Issuance of Preferred Stock	138,400,000		138,983,000	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%
Common Stock, At the Market Stock Offering, Number of Shares Sold			0
Restricted Stock Units (RSUs) [Member]
Equity [Line Items]
Stock-based compensation, issued during period (in shares)			200,799
Stock Options [Member]
Equity [Line Items]
Stock-based compensation, issued during period (in shares)			33,935
Stock Options [Member]
Equity [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			0	144,000
Restricted Stock Units (RSUs) [Member]
Equity [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			100	13,000