Employee compensation plans - Schedule of Stock Appreciation Rights (Details) - Stock Appreciation Rights (SARs)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of OARs Outstanding (in shares) | shares	2,674,512
Strike price (in dollars per share)	$ 36.87
Weighted Average Remaining Contractual Life	2 years 10 months 24 days
Fair value (in dollars per share)	$ 12.37
January 11, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of OARs Outstanding (in shares) | shares	473,956
Strike price (in dollars per share)	$ 26.45
Weighted Average Remaining Contractual Life	12 days
Fair value (in dollars per share)	$ 14.88
January 10, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of OARs Outstanding (in shares) | shares	484,790
Strike price (in dollars per share)	$ 27.54
Weighted Average Remaining Contractual Life	1 year
Fair value (in dollars per share)	$ 14.98
January 11, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of OARs Outstanding (in shares) | shares	583,389
Strike price (in dollars per share)	$ 32.16
Weighted Average Remaining Contractual Life	2 years
Fair value (in dollars per share)	$ 13.30
January 7, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of OARs Outstanding (in shares) | shares	617,707
Strike price (in dollars per share)	$ 49.57
Weighted Average Remaining Contractual Life	3 years
Fair value (in dollars per share)	$ 7.52
January 6, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of OARs Outstanding (in shares) | shares	514,670
Strike price (in dollars per share)	$ 45.33
Weighted Average Remaining Contractual Life	4 years
Fair value (in dollars per share)	$ 12.38