Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Derivatives	$ 70	$ 28
Derivatives	34	89
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Marketable Securities	267	263
Derivatives	70	28
Total Assets at Fair Value	337	291
Derivatives	34	89
Total Liabilities at Fair Value	34	89
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Marketable Securities	267	263
Derivatives	64	0
Total Assets at Fair Value	331	263
Derivatives	32	80
Total Liabilities at Fair Value	32	80
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Marketable Securities	0	0
Derivatives	6	28
Total Assets at Fair Value	6	28
Derivatives	2	9
Total Liabilities at Fair Value	2	9
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Marketable Securities	0	0
Derivatives	0	0
Total Assets at Fair Value	0	0
Derivatives	0	0
Total Liabilities at Fair Value	$ 0	$ 0