Commitments and Contingencies (Unaudited) (Details) £ in Millions	9 Months Ended
	Sep. 30, 2020 GBP (£) Rate	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs		$ 563,000,000	$ 531,000,000
Loss Contingency, Range of Possible Loss, Portion Not Accrued		439,000,000	448,000,000
Recorded Third-Party Environmental Recoveries, Amount		474,000,000	$ 436,000,000
Financial Arrangements
Standby Unused Letters Of Credit and bank guarantees		465,000,000
Surety Bond Outstanding		77,000,000
Line of Credit Facility [Line Items]
Debt Instrument, Covenant Compliance	the company was in compliance with all covenants under its credit agreements.
Two Year Term [Member] [Domain]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	£ 120	154,000,000
Line of Credit Outstanding	£ 50	64,000,000
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%
Commercial Paper [Member]
Line of Credit Facility [Line Items]
Commercial Paper, Maximum Borrowing Capacity		2,000,000,000.0
Commercial Paper		0
Other Current Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs		165,000,000
Other Noncurrent Liabilities [Member]
Site Contingency [Line Items]
Accrual for Environmental Remediation Costs		398,000,000
Other Current Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount		135,000,000
Other Noncurrent Assets [Member]
Site Contingency [Line Items]
Recorded Third-Party Environmental Recoveries, Amount		$ 339,000,000