Shareholders' Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended					0 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended		3 Months Ended	9 Months Ended
	May 23, 2013	Jun. 30, 2013	Sep. 30, 2013	May 22, 2013	Dec. 31, 2012	Feb. 20, 2012	Feb. 19, 2013 Share repurchase program 2013 [Member]	Sep. 30, 2013 Share repurchase program 2013 [Member]	Sep. 30, 2013 Share repurchase program 2013 [Member]	Feb. 19, 2013 Share Repurchase Program 2012 [Member]	May 31, 2012 Share Repurchase Program 2012 [Member]	Sep. 30, 2012 Share Repurchase Program 2012 [Member]	Sep. 30, 2012 Share Repurchase Program 2012 [Member]
Equity, Class of Treasury Stock [Line Items]
Common shares, shares authorized	305,000,000		305,000,000	120,000,000	305,000,000
Stock split, conversion ratio	3	3
Common stock dividend, percentage	200.00%	200.00%
Common stock, shares issued for stock split		117,861,772
Common shares, par value			$ 1.25		$ 1.25
Adjustments to capital in excess of par value		$ 147.3
Dividends on Common Stock, minimum						$ 0.12
Dividends on Common Stock, maximum						$ 0.14
Authorized amount to be repurchased							750				1,000
Repurchase of shares								1,115,276	6,876,380			2,478,246	12,954,255
Repurchases of shares, value								63.8	370.1			101.0	473.9
Remaining authorized repuchase capacity									$ 472.6	$ 193.0