CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
CONSOLIDATED STATEMENTS OF EQUITY
Issuance of common stock, shares		22,256,121
Restricted stock grant, forfeitures and compensation expense, shares	22,397	(161,495)
Stock options exercised, shares	11,235	97,987
Cash dividends reinvested (DRIP) in stock, shares	2,582,327	2,745,881
Cash distributions declared (in dollars per share)	$ 0.20	$ 0.20
Purchase and cancellation of common shares (in shares)		(30,585,957)
Employee stock purchase program, shares	99,533