Commitments and Contingencies (Unaudited) (Details) £ in Millions	6 Months Ended
	Jun. 30, 2019 GBP (£) Rate	Jun. 30, 2019 USD ($) Rate	Dec. 31, 2018 USD ($)
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs		$ 547,000,000	$ 461,000,000
Recorded Third-Party Environmental Recoveries, Amount		426,000,000	343,000,000
Financial Arrangements
Standby Unused Letters Of Credit and bank guarantees		489,000,000
Surety Bond Outstanding		208,000,000
Line of Credit Facility [Line Items]
Debt Instrument, Covenant Compliance	the company was in compliance with all covenants under its credit agreements.
Commercial Paper		299,000,000
Commercial Paper, Maximum Borrowing Capacity		$ 2,000,000,000.0
Commercial Paper, Weighted Average Interest Rate | Rate	2.61%	2.61%
Commercial Paper, Term	3 months
Two Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	£ 120	$ 152,000,000
Line of Credit Outstanding	£ 70	89,000,000
Five Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		2,000,000,000.0
Line of Credit Outstanding		0
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%
Other Current Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs		167,000,000
Other Noncurrent Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs		380,000,000
Other Current Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount		133,000,000
Other Noncurrent Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount		293,000,000
Environmental Issue [Member] | Maximum
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss		1,018,000,000	835,000,000
Environmental Issue [Member] | Minimum
Site Contingency [Line Items]
Loss Contingency, Estimate of Possible Loss		$ 532,000,000	$ 447,000,000