Debt, Subsequent Events (Details) € in Millions, $ in Millions	1 Months Ended			9 Months Ended
	Oct. 30, 2020 USD ($)	Oct. 30, 2020 EUR (€)	Apr. 30, 2020	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 EUR (€)
Subsequent Event [Line Items]
Proceeds from issuance of long-term debt				$ 2,492	$ 2,096
Repayments of long-term debt				500	$ 2,000
Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Maximum borrowing capacity				$ 2,500
Remaining expiration date				June 2022
Term Loan due 2022, $4,000 million [Member]
Subsequent Event [Line Items]
Maximum borrowing capacity				$ 4,000
Maturity year				2022
Senior Notes due 2021, $1,000 million, 6.0% [Member]
Subsequent Event [Line Items]
Face amount				$ 1,000
Stated interest rate (in hundredths)				6.00%		6.00%
Maturity year				2021
Guaranteed Notes due 2022, €750 million, 1.875% [Member]
Subsequent Event [Line Items]
Face amount | €						€ 750
Stated interest rate (in hundredths)				1.875%		1.875%
Maturity year				2022
Credit facility [Member]
Subsequent Event [Line Items]
Credit facility covenant terms			The Amendments amended each Credit Agreement’s leverage ratio covenant to permit netting of unrestricted cash and cash equivalents in excess of $300 million (with certain restrictions on non-US cash) and, in respect of the Senior Revolving Credit Facility and Term Loan due 2022, restrict certain dividends and other specified restricted payments.
Subsequent Event [Member] | Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Extended term borrowing capacity	$ 2,440
Extended expiration date	June 2023	June 2023
Subsequent Event [Member] | Guaranteed floating rate note due 2023 [Member]
Subsequent Event [Line Items]
Face amount	$ 650
Description of variable interest rate	The floating rate notes will bear interest equal to three-month LIBOR rate, plus 1.000% per annum	The floating rate notes will bear interest equal to three-month LIBOR rate, plus 1.000% per annum
Maturity year	2023	2023
Description of debt redemption terms	These notes may be redeemed on or after the date that is two years prior to the scheduled maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest	These notes may be redeemed on or after the date that is two years prior to the scheduled maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest
Subsequent Event [Member] | 1.25% Guaranteed notes due 2025 [Member]
Subsequent Event [Line Items]
Face amount	$ 500
Stated interest rate (in hundredths)	1.25%
Maturity year	2025	2025
Discounted prices at which long-term debt was issued (in thousandths)	99.683%
Description of debt redemption terms	These notes may be redeemed before the date that is one month prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 15 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is one month prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.	These notes may be redeemed before the date that is one month prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 15 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is one month prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.
Subsequent Event [Member] | 2.25% Guaranteed notes due 2030 [Member]
Subsequent Event [Line Items]
Face amount	$ 500
Stated interest rate (in hundredths)	2.25%
Maturity year	2030	2030
Discounted prices at which long-term debt was issued (in thousandths)	99.203%
Description of debt redemption terms	These notes may be redeemed before the date that is three months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 25 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is three months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.	These notes may be redeemed before the date that is three months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 25 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is three months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.
Subsequent Event [Member] | Guaranteed notes due 2040 [Member]
Subsequent Event [Line Items]
Face amount	$ 750
Stated interest rate (in hundredths)	3.375%
Maturity year	2040	2040
Discounted prices at which long-term debt was issued (in thousandths)	99.77%
Description of debt redemption terms	These notes may be redeemed before the date that is six months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 30 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is six months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.	These notes may be redeemed before the date that is six months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 30 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is six months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.
Subsequent Event [Member] | Guaranteed notes due 2051 [Member]
Subsequent Event [Line Items]
Face amount	$ 1,000
Stated interest rate (in hundredths)	3.625%
Maturity year	2051	2051
Discounted prices at which long-term debt was issued (in thousandths)	99.707%
Description of debt redemption terms	These notes may be redeemed before the date that is six months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 35 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is six months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.	These notes may be redeemed before the date that is six months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 35 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is six months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.
Subsequent Event [Member] | Guaranteed Notes due 2060 [Member]
Subsequent Event [Line Items]
Face amount	$ 500
Stated interest rate (in hundredths)	3.80%
Maturity year	2060	2060
Discounted prices at which long-term debt was issued (in thousandths)	99.166%
Description of debt redemption terms	These notes may be redeemed before the date that is six months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 35 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is six months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.	These notes may be redeemed before the date that is six months prior to the scheduled maturity date at a redemption price equal to the greater of (i) 100% of the principal amount of the notes redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest (discounted at the applicable treasury yield plus 35 basis points) on the notes to be redeemed. These notes may also be redeemed on or after the date that is six months prior to the final maturity date of the notes at a redemption price equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest.
Subsequent Event [Member] | Guaranteed 1.25% 2025 notes, 2.25% 2030 notes and 2060 notes [Member]
Subsequent Event [Line Items]
Description of debt redemption terms	If the Louisiana Joint Venture transaction does not close on or prior to March 31, 2021, or is terminated on or prior to completion, we will be required to redeem all of the outstanding 1.25% 2025 Notes, 2.25% 2030 Notes and 2060 Notes at a redemption price equal to 101% of the aggregate principal amount plus accrued and unpaid interest for each of these notes	If the Louisiana Joint Venture transaction does not close on or prior to March 31, 2021, or is terminated on or prior to completion, we will be required to redeem all of the outstanding 1.25% 2025 Notes, 2.25% 2030 Notes and 2060 Notes at a redemption price equal to 101% of the aggregate principal amount plus accrued and unpaid interest for each of these notes
Subsequent Event [Member] | Guaranteed notes due 2023, 2025, 2030, 2040, 2051, and 2060 [Member]
Subsequent Event [Line Items]
Issuance date	October 2020	October 2020
Proceeds from issuance of long-term debt	$ 3,848
Restrictive debt covenants	The indenture governing the October Notes contains limited covenants, including those restricting our ability and the ability of our subsidiaries to incur indebtedness secured by significant property or by capital stock of subsidiaries that own significant property, enter into certain sale and lease-back transactions with respect to any significant property or enter into consolidations, mergers or sales of all or substantially all of our assets	The indenture governing the October Notes contains limited covenants, including those restricting our ability and the ability of our subsidiaries to incur indebtedness secured by significant property or by capital stock of subsidiaries that own significant property, enter into certain sale and lease-back transactions with respect to any significant property or enter into consolidations, mergers or sales of all or substantially all of our assets
Subsequent Event [Member] | Term Loan due 2022, $4,000 million [Member]
Subsequent Event [Line Items]
Maturity year	2022	2022
Repayments of long-term debt	$ 500
Subsequent Event [Member] | Senior Notes due 2021, $1,000 million, 6.0% [Member]
Subsequent Event [Line Items]
Stated interest rate (in hundredths)	6.00%
Maturity year	2021	2021
Repayments of long-term debt	$ 1,000
Subsequent Event [Member] | Guaranteed Notes due 2022, €750 million, 1.875% [Member]
Subsequent Event [Line Items]
Stated interest rate (in hundredths)	1.875%
Maturity year	2022	2022
Repayments of long-term debt | €		€ 750
Subsequent Event [Member] | Senior notes due 2021, and guaranteed note due 2022 [Member]
Subsequent Event [Line Items]
Payment of debt redemption costs	$ 116
Write off of unamortized debt issuance cost	4
Write-off of the cumulative fair value hedge accounting adjustment	$ 12
Subsequent Event [Member] | Credit facility [Member]
Subsequent Event [Line Items]
Credit facility covenant terms	maximum leverage ratio (calculated as the ratio of total net funded debt to consolidated earnings before interest, taxes and depreciation and amortization, both as defined in our Credit Agreements) financial covenant to (i) 4.25 to 1.00 for the fiscal quarter ending December 31, 2020; (ii) 4.50 to 1.00 for the fiscal quarter ending March 31, 2021; (iii) 4.00 to 1.00 for the fiscal quarter ending June 30, 2021; (iv) 3.75 to 1.00 for the fiscal quarter ending September 30, 2021; and (v) 3.50 to 1.00 for the fiscal quarter ending December 31, 2021 and thereafter; provided, that, to the extent our recently announced Louisiana Joint Venture is consummated, the maximum leverage ratio financial covenant will automatically adjust to (i) 5.00 to 1.00 for the fiscal quarters ending December 31, 2020 and March 31, 2021; (ii) 4.75 to 1.00 for the fiscal quarter ending June 30, 2021; (iii) 4.50 to 1.00 for the fiscal quarters ending September 30, 2021 and December 31, 2021; (iv) 4.00 to 1.00 for the fiscal quarter ending March 30, 2022; (v) 3.50 to 1.00 for the fiscal quarter ending June 30, 2022 (or, if the Louisiana Joint Venture is consummated after December 31, 2020, 4.00 to 1.00); and (vi) 3.50 to 1.00 for the fiscal quarter ending September 30, 2022 and thereafter. In addition, with respect to the Senior Revolving Credit Facility and the Term Loan due 2022, the October Amendments further restrict certain dividends and other specified restricted payments.	maximum leverage ratio (calculated as the ratio of total net funded debt to consolidated earnings before interest, taxes and depreciation and amortization, both as defined in our Credit Agreements) financial covenant to (i) 4.25 to 1.00 for the fiscal quarter ending December 31, 2020; (ii) 4.50 to 1.00 for the fiscal quarter ending March 31, 2021; (iii) 4.00 to 1.00 for the fiscal quarter ending June 30, 2021; (iv) 3.75 to 1.00 for the fiscal quarter ending September 30, 2021; and (v) 3.50 to 1.00 for the fiscal quarter ending December 31, 2021 and thereafter; provided, that, to the extent our recently announced Louisiana Joint Venture is consummated, the maximum leverage ratio financial covenant will automatically adjust to (i) 5.00 to 1.00 for the fiscal quarters ending December 31, 2020 and March 31, 2021; (ii) 4.75 to 1.00 for the fiscal quarter ending June 30, 2021; (iii) 4.50 to 1.00 for the fiscal quarters ending September 30, 2021 and December 31, 2021; (iv) 4.00 to 1.00 for the fiscal quarter ending March 30, 2022; (v) 3.50 to 1.00 for the fiscal quarter ending June 30, 2022 (or, if the Louisiana Joint Venture is consummated after December 31, 2020, 4.00 to 1.00); and (vi) 3.50 to 1.00 for the fiscal quarter ending September 30, 2022 and thereafter. In addition, with respect to the Senior Revolving Credit Facility and the Term Loan due 2022, the October Amendments further restrict certain dividends and other specified restricted payments.