Equity Equity, Textuals (Details) (USD $)	3 Months Ended			9 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Dividends declared per share		$ 0.05	$ 0.04	$ 0.15	$ 0.12
Dividends, Common Stock, Cash		$ 11,400,000
Stock Repurchase Program, Authorization Increase				116,600,000
Stock Repurchase Program, Authorized Amount				200,000,000
Treasury Stock, Shares, Acquired		1,233,800		14,641,168
Treasury Stock, Value, Acquired, Par Value Method		11,700,000		145,000,000
Treasury Stock Acquired, Average Cost Per Share		$ 9.48		$ 9.90
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 138,600,000			$ 150,270,000