Financing arrangements - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Debt Instrument [Line Items]
Extinguishment of debt	$ 410
Gain (loss) on extinguishment of debt	$ 133
Notes | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate	1.225%
4.563% notes due 2048 (4.563% 2048 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	4.563%
Effective interest rate	6.30%
4.663% notes due 2051 (4.663% 2051 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	4.663%
Effective interest rate	5.60%
2.77% notes due 2053 (2.77% 2053 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	2.77%
Effective interest rate	5.20%
3.15% notes due 2040 (3.15% 2040 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	3.15%
2.80% notes due 2041 (2.80% 2041 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	2.80%
3.375% notes due 2050 (3.375% 2050 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	3.375%
3.00% notes due 2052 (3.00% 2052 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	3.00%
4.20% notes due 2052 (4.20% 2052 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	4.20%
4.40% notes due 2062 (4.40% 2062 Notes) | Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	4.40%