Shareholders' Equity (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	12 Months Ended
	Jun. 14, 2007	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Shareholders' Equity [Abstract]
Common shares, authorized		200,000,000
Common shares, par value		$ 1	$ 1
Preference shares, authorized		500,000
Preference shares, outstanding			0	0
Repurchase of outstanding common stock, authorized amount	$ 300
Shares purchased under Board authorization		0
Weighted average antidilutive which were not included in the calculation of earnings per share		8,825,000	4,391,000	1,677,000