Lease Commitments - Lease Maturity (Details) $ in Millions	Dec. 31, 2020 USD ($)
Operating Leases
2021	$ 226
2022	209
2023	160
2024	130
2025	110
Thereafter	382
Total undiscounted future minimum lease payments	1,217
Less: Imputed interest	(116)
Present value of lease liabilities	1,101
Finance Leases
2021	31
2022	20
2023	18
2024	18
2025	10
Thereafter	0
Less: Imputed interest	97
Less: Imputed interest	(2)
Present value of lease liabilities	95
Total
2021	257
2022	229
2023	178
2024	148
2025	120
Thereafter	382
Total undiscounted future minimum lease payments	1,314
Less: Imputed interest	(118)
Present value of lease liabilities	$ 1,196

Finance And Operating Lease Liability, Payments, Net Of Sublease Income, Due Year One

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Financing And Operating Lease Liability, Net Of Sublease Income

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Financing And Operating Lease Liability, Net Of Sublease Income, Undiscounted Excess Amount

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Financing And Operating Lease Liability, Payments, Net Of Sublease Income, Due

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Financing And Operating Lease Liability, Payments, Net Of Sublease Income, Due After Year Five

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Financing And Operating Lease Liability, Payments, Net Of Sublease Income, Due Year Five

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Financing And Operating Lease Liability, Payments, Net Of Sublease Income, Due Year Four

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Financing And Operating Lease Liability, Payments, Net Of Sublease Income, Due Year Three

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Financing And Operating Lease Liability, Payments, Net Of Sublease Income, Due Year Two

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Leases Maturity [Abstract]

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Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of lessee's undiscounted obligation for lease payment for operating lease.

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Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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