Commitments and Contingencies (Unaudited) (Details) £ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Rate	Jun. 30, 2017 USD ($)	Jun. 30, 2018 GBP (£) Rate	Jun. 30, 2018 USD ($) Rate	Dec. 31, 2017 USD ($)
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs						$ 463,000,000	$ 410,000,000
Recorded Third-Party Environmental Recoveries, Amount						236,000,000	207,000,000
Financial Arrangements
Standby Unused Letters Of Credit and bank guarantees						395,000,000
Surety Bond Outstanding						211,000,000
Operating leases
Rental expense for operating leases, net of immaterial amounts of sublease rental income	$ 81,000,000	$ 65,000,000	$ 173,000,000	$ 154,000,000
Line of Credit Facility [Line Items]
Debt Instrument, Covenant Compliance			the company was in compliance with all covenants under its credit agreements.
Short Term Debt, Maximum Borrowing Capacity						750,000,000
Debt Instrument, Term			90 days
Commercial Paper						$ 249,000,000
Short-term Debt, Weighted Average Interest Rate, at Point in Time | Rate					2.46%	2.46%
Two Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					£ 120	$ 159,000,000
Line of Credit Outstanding					£ 90	119,000,000
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
Other Current Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs						155,000,000
Other Noncurrent Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs						308,000,000
Other Current Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount						79,000,000
Other Noncurrent Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount						157,000,000
London Interbank Offered Rate (LIBOR) [Member] | Two Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate During Period | Rate			1.10%
Environmental Issue [Member] | Maximum
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss						836,000,000	792,000,000
Environmental Issue [Member] | Minimum
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss						$ 453,000,000	$ 405,000,000