Stock-based compensation - Summary of Deferred Share Units Plan (Details) - DSUs - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] (in shares)
Outstanding, January 1 (in shares)	744,530	841,333
Granted (in shares)	85,750	60,262
PDSUs converted into DSUs (in shares)	(81,533)	0
Issued in lieu of dividends (in shares)	5,685	6,510
Settled (in shares)	(15,935)	(162,319)
Forfeited (in shares)	(1,745)	(1,256)
Outstanding, December 31 (in shares)	899,818	744,530