Shareholders' Equity (Details) (USD $)	3 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 12, 2012	Dec. 31, 2011	Feb. 17, 2014	May 23, 2013	May 22, 2013	Feb. 19, 2013	Feb. 16, 2015	Nov. 18, 2014	May 31, 2012	Feb. 18, 2013	Jun. 15, 2012
Common stock, shares authorized		305,000,000	305,000,000					305,000,000.0	120,000,000.0
Stock split, conversion ratio	3
Common Stock Dividends, Shares, Percentage	200.00%
Stock Issued During Period, Shares, Stock Splits	117,861,772
Common shares, par value	$ 1.25	$ 1.25	$ 1.25
Adjustments to Additional Paid in Capital, Stock Split	$ 147,300,000
Dividend Per Common Share Minimum							$ 0.14			$ 0.12
Dividend Per Common Share Maximum							$ 0.16			$ 0.14
Stock Repurchase Program, Remaining Authorized Repurchase Amount		464,400,000
Treasury stock, acquired		246,504,000	458,310,000	771,942,000
Subsequent Event
Dividend Per Common Share Minimum											$ 0.16
Dividend Per Common Share Maximum											$ 0.18
Share Repurchase Program 2012
Stock Repurchase Program, Authorized Amount													1,000,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount												175,000,000
Treasury stock, shares acquired					8,142,723
Treasury stock, acquired			458,300,000
Share repurchase program 2013
Stock Repurchase Program, Authorized Amount												500,000,000		750,000,000
Treasury stock, shares acquired		3,420,656
Treasury stock, acquired		246,500,000
ASR Program
Stock Repurchase Program, Authorized Amount															300,000,000
Treasury stock, shares acquired			7,243,191
Treasury stock acquired, weighted average price per share			$ 42.31
Share Repurchase Program 2011
Treasury stock, shares acquired						18,638,340
Treasury stock, acquired						$ 771,900,000