Commitments and Contingencies (Unaudited) (Details) £ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2017 GBP (£)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 GBP (£)	Dec. 31, 2016 USD ($)	Jul. 31, 2015 USD ($)
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs				$ 402,000,000		$ 385,000,000
Recorded Third-Party Environmental Recoveries, Amount				207,000,000		195,000,000
Financial Arrangements
Standby Unused Letters Of Credit and bank guarantees				205,000,000
Surety Bond Outstanding				202,000,000
Operating leases
Rental expense for operating leases, net of immaterial amounts of sublease rental income	$ 89,000,000	$ 91,000,000
Line of Credit Facility [Line Items]
Debt Instrument, Covenant Compliance	the company was in compliance with all covenants under the Credit Agreements.
Other Current Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs				127,000,000
Other Noncurrent Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs				275,000,000
Inventoried Costs [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount				71,000,000
Other Noncurrent Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount				136,000,000
Two Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				150,000,000	£ 120
Line of Credit Outstanding			£ 110	137,000,000
Line of Credit Facility, Interest Rate Description	LIBOR plus 1.10 percent
Five Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity							$ 1,600,000,000
Line of Credit Outstanding				0
Environmental Issue [Member] | Maximum
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss				790,000,000		774,000,000
Environmental Issue [Member] | Minimum
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss				$ 399,000,000		$ 379,000,000