Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Derivatives	$ 13	$ 28
Derivatives	83	89
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Marketable Securities	268	263
Derivatives	13	28
Total Assets at Fair Value	281	291
Derivatives	83	89
Total Liabilities at Fair Value	83	89
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Marketable Securities	268	263
Derivatives	0	0
Total Assets at Fair Value	268	263
Derivatives	63	80
Total Liabilities at Fair Value	63	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	13	28
Total Assets at Fair Value	13	28
Derivatives	20	9
Total Liabilities at Fair Value	20	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