Equity Equity, Textuals (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Common Stock, Shares Authorized	500,000,000	500,000,000	500,000,000
Common Stock, Shares, Outstanding	222,955,853	222,955,853	241,035,250
Treasury Stock, Shares	1,709,542	1,709,542	984,400
Treasury Stock, Shares, Acquired	1,831,921	19,752,174	13,927,510
Treasury Stock, Value, Acquired, Par Value Method	$ 20,000,000	$ 195,700,000	$ 116,200,000
Treasury Stock Acquired, Average Cost Per Share	$ 10.90	$ 9.91	$ 8.34
Stock Repurchase Program, Authorization Increase		116,600,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	199,400,000	99,600,000
Dividends declared per share	$ 0.05	$ 0.20	$ 0.16	$ 0.16
Dividends, Common Stock, Cash	11,000,000
Payments of Dividends, Common Stock		$ 44,795,000	$ 40,001,000	$ 40,195,000