Equity (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended				1 Months Ended	3 Months Ended		25 Months Ended	26 Months Ended
	Mar. 31, 2011	Mar. 31, 2013	Mar. 31, 2012	Apr. 25, 2013	Mar. 12, 2013	Apr. 19, 2013 Treasury Stock	Mar. 31, 2013 Treasury Stock	Mar. 31, 2012 Treasury Stock	Mar. 31, 2013 Treasury Stock	Apr. 19, 2013 Treasury Stock
Treasury stock shares acquired						205,814	164,120	79,000	4,500,000	4,700,000
Treasury stock value acquired cost method		$ 12,480,000	$ 4,924,000			$ 16,100,000	$ 12,480,000	$ 4,924,000	$ 256,400,000	$ 272,500,000
Authorized Repurchase of common stock	1,500,000,000
Dividends Payable, Amount Per Share					$ 0.26
Dividends Payable				102,800,000
Accrued Dividend RSU		500,000
Remaining Stock Value Of Buyback							$ 1,200,000,000