Fair Value Measurements (Narrative) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in money market mutual funds classified as cash and cash equivalents	$ 422,000,000
Common Stock and Equivalents | U.S. Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	117,000,000	173,000,000
Common Stock and Equivalents | Non-U.S. Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	29,000,000
Common Stock and Equivalents | Postretirement Health Care Plan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	4,000,000	6,000,000
U.S. Government And Agency Obligations | U.S. Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	260,000,000	182,000,000
U.S. Government And Agency Obligations | Non-U.S. Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	2,000,000
U.S. Government And Agency Obligations | Postretirement Health Care Plan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	7,000,000	6,000,000
Corporate Bonds | U.S. Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	17,000,000	39,000,000
Corporate Bonds | Non-U.S. Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	27,000,000
Corporate Bonds | Postretirement Health Care Plan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement		1,000,000
Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, Fair Value	2,100,000,000
Carrying (Reported) Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, Fair Value	$ 1,900,000,000