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Financial Instruments - Fair Value of Hedges (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Loans payable and current portion of long-term debt
Derivative [Line Items]
Carrying Amount of Hedged Liabilities	$ 1,150	$ 1,249
Cumulative Amount of Fair Value Hedging Adjustment Increase (Decrease) Included in the Carrying Amount	0	(1)
Long-Term Debt
Derivative [Line Items]
Carrying Amount of Hedged Liabilities	2,301	3,409
Cumulative Amount of Fair Value Hedging Adjustment Increase (Decrease) Included in the Carrying Amount	$ 53	$ 14

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- Definition

Amount of liability hedged in fair value hedging relationship.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4EE
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109999712-113959

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109999712-113959

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