Share-based payments (Tables)

3 Months Ended

Mar. 31, 2022

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Compensation Costs Related to Share-Based Payments

	Three months ended
	March 31,
	2022		2021
SG&A expenses:
Stock option compensation expense	$	2,567	$	1,861
Equity-classified share units		2,890		3,153
Liability-classified share units		(756)		(1,915)
Employee share purchase plan - employer contributions		685		679
		5,386		3,778
Acquisition-related costs:
Share-based continuing employment costs		2,133		2,553
		2,133		2,553
	$	7,519	$	6,331

Summary of Stock Option Activity

	Stock options							Premium-priced stock options
				WA							WA
	Common	WA		remaining		Aggregate		Common	WA		remaining		Aggregate
	shares under	exercise		contractual		intrinsic		shares under	exercise		contractual		intrinsic
	option	price		life (in years)		value		option	price		life (in years)		value
Outstanding, December 31, 2021	2,208,057		42.55		7.7		41,884	1,017,064		91.24		5.7		—
Granted	629,877		57.70		—		—	—		—		—		—
Exercised	(25,942)		38.01		—		573	—		—		—		—
Forfeited	(6,255)		43.02		—		—	(9,576)		90.93		—		—
Outstanding, March 31, 2022	2,805,737		45.99		8.0		37,437	1,007,488		91.24		5.4		—
Exercisable, March 31, 2022	1,338,173		37.19		6.7		29,251	1,192		90.93		5.6		—

Summary of Share Unit Activity

	Equity-classified awards									Liability-classified awards
	PSUs			PSUs with Market Conditions			RSUs			DSUs
		WA grant			WA grant			WA grant				WA grant
		date fair			date fair			date fair				date fair
	Number	value		Number	value		Number	value			Number	value
Outstanding, December 31, 2021	523,618	$	45.90	88,305	$	65.45	79,112	$	54.96		156,589	$	35.28
Granted	151,873		57.52	—		—	33,440		57.67		5,966		54.27
Vested and settled	(93,241)		36.42	—		—	(21,221)		46.43		—		—
Forfeited	(1,165)		50.35	—		—	(866)		54.15		—		—
Outstanding, March 31, 2022	581,085	$	50.45	88,305	$	65.45	90,465	$	57.97		162,555	$	35.97

Stock Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Significant Assumptions Used to Estimate the Fair Value of Stock Options

Three months ended March 31,	2022		2021
Risk free interest rate	2.1	%	0.5	%
Expected dividend yield	1.75	%	1.66	%
Expected lives of the stock options	4	years	4	years
Expected volatility	31.7	%	32.3	%