Shareholders' Equity and Per Share Data (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Class of Stock [Line Items]
Capital Units, Authorized	6,620,000,000
Common Stock, Shares Authorized	6,500,000,000	6,500,000,000
Common Stock, Par or Stated Value Per Share	$ 2	$ 2
Preferred Stock, Shares Authorized	20,000,000
Percent Of One Vote Per Share Common Stock	10.00%
Stock Issued During Period, Value, Conversion of Convertible Securities		$ 0
Potentially Dilutive Shares With Average Market Price Greater Than Exercise Price	44,000,000	27,000,000	30,000,000
Series 1 Voting [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	6,000,000,000
Common Stock, Par or Stated Value Per Share	$ 2.00
Common Stock, Shares, Outstanding	3,000,000,000
Stock Issued During Period, Shares, Conversion of Convertible Securities	35,000,000
Series 2 Voting [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	500,000,000
Common Stock, Par or Stated Value Per Share	$ 2.00
Stock Issued During Period, Shares, Conversion of Convertible Securities	(35,000,000)
Non Voting [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	100,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01
Common Stock [Member]
Class of Stock [Line Items]
Stock Issued During Period, Value, Conversion of Convertible Securities	38
Additional Paid-in Capital [Member]
Class of Stock [Line Items]
Stock Issued During Period, Value, Conversion of Convertible Securities	168
Treasury Stock [Member]
Class of Stock [Line Items]
Stock Issued During Period, Value, Conversion of Convertible Securities	$ 206