Shareholders' Equity (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended
	May 01, 2012	Mar. 31, 2012	Dec. 31, 2011
Schedule Of Shareholders Equity [Line Items]
Common stock shares authorized		2,000,000,000	2,000,000,000
Common shares, par value		$ 5	$ 5
Common shares outstanding		698,454,000	697,143,000
Preferred shares authorized		5,000,000	5,000,000
Preferred shares outstanding		0	0
Preferred Stock, Value, Outstanding	$ 575
Preferred Stock, Dividend Rate, Percentage	5.85%