Share-based compensation - Performance Shares Activity (Details) - Performance shares	12 Months Ended
	Dec. 31, 2023 $ / shares shares	Dec. 31, 2023 € / shares shares	Dec. 31, 2022 $ / shares shares	Dec. 31, 2022 € / shares shares	Dec. 31, 2021 $ / shares shares	Dec. 31, 2021 € / shares shares
Number of shares
Outstanding at beginning of year (in shares)	10,178,940	10,178,940
Granted (in shares)	2,979,818	2,979,818
Forfeited (in shares)	(356,840)	(356,840)
Vested (in shares)	(2,985,299)	(2,985,299)	(3,084,926)	(3,084,926)	(2,915,761)	(2,915,761)
Outstanding at end of year (in shares)	9,816,619	9,816,619	10,178,940	10,178,940
Weighted average grant date fair value
Outstanding at beginning of year (in usd or eur per share) | (per share)	$ 36.25	€ 32.52
Granted (in usd or eur per share) | (per share)	48.55	45.57	$ 36.29	€ 34.50	$ 42.05	€ 35.40
Forfeited (in usd or eur per share) | (per share)	37.45	33.97
Vested (in usd or eur per share) | (per share)	30.95	27.70
Outstanding at beginning of year (in usd or eur per share) | (per share)	$ 41.56	€ 37.90	$ 36.25	€ 32.52