Financial Instruments and Fair Value Measurements, Carrying value and estimated fair value of non-derivative financial instruments (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Liabilities: [Abstract]
Short-term debt, carrying value	$ 616	$ 445
Nonrecurring [Member] \| Non-derivatives: [Member]
Liabilities: [Abstract]
Short-term debt, carrying value	138	181
Long-term debt, carrying value	13,755	11,609
Total liabilities, carrying value	13,893	11,790
Short-term debt, fair value	147	215
Long-term debt, fair value	15,132	12,561
Total liabilities, fair value	$ 15,279	$ 12,776
Non-derivative fair value level and transfers description	All financial instruments in the table above are classified as Level 2.

Carrying value of financial and nonfinancial obligations.

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- Definition

All non-derivative financial instruments measured at fair value on a non-recurring basis are classified as Level 2 in the fair value hierarchy.

+ References

No definition available.

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- References

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Fair value of financial and nonfinancial obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Topic 470
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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.

+ References

No definition available.

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