CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - Unaudited (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2013
Stockholders' Equity Attributable to Parent
Common dividends declared - per share (in dollars per share)	$ 0.53
Issuance of shares of common stock, common stock offering, net of expenses	245,010
Issuance of shares of common stock, options exercised	0
Issuance of shares of common stock, dividend reinvestment plan	933
Withheld shares of common stock to satisfy tax withholding obligations in connection with the vesting of restricted stock	9,412