Stock-based compensation - Summary of incentive plan for members of the Board of Directors (Details) - Restricted Stock Units (RSUs) - Directors - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Roll Forward
Non-vested at beginning of period	0	0	0
Granted	25,321	20,638	43,866
Vested	(25,321)	(20,638)	(43,866)
Forfeited	0	0	0
Non-vested at end of period	0	0	0
Weighted-Average Grant Date Fair Value
Non-vested at beginning of period	$ 0	$ 0	$ 0
Granted	77.48	78.20	35.47
Vested	77.48	78.20	35.47
Forfeited	0	0	0
Non-vested at end of period	$ 0	$ 0	$ 0