Leases (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Lease, Cost [Abstract]
Operating Lease Cost		$ 295	$ 393	[1]	$ 497
Amortization of Lease Assets		39	21		13
Interest on Lease Liabilities		7	4		2
Variable Lease Cost		63	91		138
Short-term Lease Cost		257	194		333
Total Lease Cost		661	703		983
Operating Lease, Impairment Expense			35
Lease Assets and Liabilities [Abstract]
Total		984	1,075
Current Portion of Operating Lease Liabilities		240	295
Total		$ 1,048	$ 1,148
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]		Other Assets, Noncurrent	Other Assets, Noncurrent
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]		Property, Plant and Equipment, Gross	Property, Plant and Equipment, Gross
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]		Current Portion of Long-Term Debt	Current Portion of Long-Term Debt
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Other Liabilities	Other Liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Long-Term Debt	Long-Term Debt
Cash Flow Operating And Financing Activities [Abstract]
Repayment of Finance Lease Liabilities		$ 37	$ 19		13
Operating Leases Non-Cash Leasing Activities		333	893		784
Finance Leases Non-Cash Leasing Activities		74	174
Operating And Finance Leases Future Minimum Payments [Abstract]
Total Lease Liabilities		250	$ 212
Operating And Finance Leases Not Yet Commenced		$ 98
Minimum Operating And Finance Leases Not Yet Commenced Lease Term		3 months
Maximum Operating And Finance Leases Not Yet Commenced Lease Term		9 years
Accounting Standards Update 2016-02
Lease Assets and Liabilities [Abstract]
Other Assets						$ 566
Operating Leases
Lease Assets and Liabilities [Abstract]
Current Portion of Operating Lease Liabilities		$ 240
Other Liabilities		$ 558
Weighted Average Remaining Lease Term And Discount Rate [Abstract]
Operating Lease Weighted Average Remaining Lease Term (in years)		5 years 3 months 18 days	5 years 3 months 18 days
Operating Lease Weighted Average Discount Rate (%)		3.00%	3.40%
Operating And Finance Leases Future Minimum Payments [Abstract]
2022		$ 262
2023		188
2024		113
2025		80
2026		59
2027 and Beyond		172
Total Lease Payments		874
Less: Discount to Present Value		76
Total Lease Liabilities		798
Operating Leases | Operating Activities
Cash Flow Operating And Financing Activities [Abstract]
Repayment of Operating Lease Liabilities Associated with Operating Activities		207	$ 223		225
Operating Leases | Investing Activities
Cash Flow Operating And Financing Activities [Abstract]
Repayment of Operating Lease Liabilities Associated with Operating Activities		98	$ 130		270
Finance Leases
Lease Assets and Liabilities [Abstract]
Current Portion of Long-Term Debt		37
Long-Term Debt		$ 213
Weighted Average Remaining Lease Term And Discount Rate [Abstract]
Finance Lease Weighted Average Remaining Lease Term (in years)		7 years	7 years 7 months 6 days
Finance Lease Weighted Average Discount Rate (%)		2.60%	2.80%
Cash Flow Operating And Financing Activities [Abstract]
Repayment of Finance Lease Liabilities		$ 37	$ 19		$ 13
Operating And Finance Leases Future Minimum Payments [Abstract]
2022		42
2023		37
2024		37
2025		36
2026		30
2027 and Beyond		94
Total Lease Payments		276
Less: Discount to Present Value		26
Total Lease Liabilities		250
Other Assets | Operating Leases
Lease Assets and Liabilities [Abstract]
Other Assets		743	869
Property, Plant and Equipment | Finance Leases
Lease Assets and Liabilities [Abstract]
Property, Plant and Equipment, Net (1)	[2]	241	206
Finance Lease, Right-of-Use Asset, Accumulated Amortization		119	81
Current Portion of Operating Lease Liabilities | Operating Leases
Lease Assets and Liabilities [Abstract]
Current Portion of Operating Lease Liabilities		240	295
Current Portion of Long-Term Debt | Finance Leases
Lease Assets and Liabilities [Abstract]
Current Portion of Long-Term Debt		37	31
Other Liabilities | Operating Leases
Lease Assets and Liabilities [Abstract]
Other Liabilities		558	641
Long-term Debt | Finance Leases
Lease Assets and Liabilities [Abstract]
Long-Term Debt		$ 213	$ 181

[1] Operating lease cost includes impairment expenses of $35 million in 2020.

[2] Finance lease assets are recorded net of accumulated amortization of $119 million and $81 million at December 31, 2021 and 2020, respectively.