Debt and lines of credit - Schedule of Long-term Debt Outstanding (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total debt	$ 7,800	$ 6,850
Net unamortized discounts, premiums and issuance costs	(61)	(52)
Total debt, including net unamortized discounts, premiums and issuance costs	7,739	6,798
Current portion of long-term debt	(500)	(550)
Long-term debt	$ 7,239	6,248
Notes due 2021 at 2.75%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	2.75%
Total debt	$ 0	550
Notes due 2022 at 1.85%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	1.85%
Total debt	$ 500	500
Notes due 2023 at 2.25%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	2.25%
Total debt	$ 500	500
Notes due 2024 at 2.625%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	2.625%
Total debt	$ 300	300
Notes due 2025 at 1.375%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	1.375%
Total debt	$ 750	750
Notes due 2026 at 1.125%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	1.125%
Total debt	$ 500	0
Notes due 2027 at 2.90%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	2.90%
Total debt	$ 500	500
Notes due 2029 at 2.25%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	2.25%
Total debt	$ 750	750
Notes due 2030 at 1.75%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	1.75%
Total debt	$ 750	750
Notes due 2031 at 1.90%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	1.90%
Total debt	$ 500	0
Notes due 2039 at 3.875%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	3.875%
Total debt	$ 750	750
Notes due 2048 at 4.15%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	4.15%
Total debt	$ 1,500	1,500
Notes due 2051 at 2.70%
Debt Instrument [Line Items]
Long-term debt stated interest rate (in percentage)	2.70%
Total debt	$ 500	$ 0

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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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.

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