Fair Value Measurements (Narrative) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
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	$ 1,300,000,000	$ 3,300,000,000
Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, Fair Value	4,100,000,000
Carrying (Reported) Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, Fair Value	4,400,000,000
Non - U.S. Pension Benefit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	0
Non - U.S. Pension Benefit | Common stock and equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement		16,000,000
Non - U.S. Pension Benefit | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement		12,000,000
U.S. Pension Benefit Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	0	0
Postretirement Health Coverage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement		$ 0
Postretirement Health Coverage | Common stock and equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities lending arrangement	$ 0