Share-based compensation (Tables)

12 Months Ended

Dec. 31, 2019

Share-Based Payment Arrangements [Abstract]

Changes in number and exercise prices of other equity instruments

Deferred, restricted and performance share units (old plan and new plan) outstanding as at December 31, 2019 and 2018 are as follows:



	Number of deferred share units		Number of restricted share units		Number of performance share units (old plan)		Number of performance share units (new plan)
Outstanding at December 31, 2017	224,846		20,455		604,895		—
Granted	7,752		8,700		149,200		—
Performance factor impact on redemption¹	—		—		(127,733	)	—
Granted in lieu of dividends	4,495		545		12,303		—
Redeemed	(28,001	)	(12,339	)	(42,577	)	—
Cancelled	—		—		(16,310	)	—
Outstanding at December 31, 2018	209,092		17,361		579,778		—
Granted	14,158		79,240		—		134,930
Performance factor impact on redemption¹	—		—		132,215		—
Granted in lieu of dividends	4,031		2,840		9,909		4,464
Redeemed	(137,515	)	(15,428	)	(396,635	)	—
Cancelled	—		(845	)	(21,822	)	(1,356	)
Outstanding at December 31, 2019	89,766		83,168		303,445		138,038


¹	Performance share units granted prior to 2019 have a feature where the ultimate number of units that vest are adjusted by a performance factor of the original grant as determined by the Company's total shareholder return in relation to a predetermined target over the period to vesting. These units relate to performance share units redeemed in the quarter ended March 31, 2018 and March 31, 2019.

All SARs and TSARs granted have a maximum term of seven years with one-third vesting each year after the date of grant. SARs and TSARs units outstanding at December 31, 2019 and 2018 are as follows:



	SARs				TSARs

	Number of units		Exercise price USD		Number of units		Exercise price USD
Outstanding at December 31, 2017	1,450,077		$	45.11	2,043,495		$	46.62
Granted	141,300		55.28		330,400		55.37
Exercised	(669,931	)	39.00		(918,327	)	42.48
Cancelled	(16,582	)	53.12		(8,267	)	47.25
Expired	(7,981	)	28.74		—		—
Outstanding at December 31, 2018	896,883		$	51.27	1,447,301		$	51.24
Granted	29,320		57.60		294,680		56.70
Exercised	(39,662	)	37.25		(45,769	)	37.08
Cancelled	(29,134	)	54.72		(34,885	)	53.38
Outstanding at December 31, 2019	857,407		$	52.02	1,661,327		$	52.55

Number and weighted average remaining contractual life of SARs and TSARs outstanding and exercisable

Information regarding the SARs and TSARs outstanding as at December 31, 2019 is as follows:



	Units outstanding at December 31, 2019				Units exercisable at December 31, 2019

Range of exercise prices	Weighted average remaining contractual life (years)	Number of units outstanding	Weighted average exercise price		Number of units exercisable	Weighted average exercise price
SARs
$25.97 to $35.51	3.17	186,980	$	34.59	186,980	$	34.59
$38.24 to $50.17	2.91	191,684	46.39		141,597	45.07
$54.65 to $78.59	2.91	478,743	61.08		362,759	62.73
	2.97	857,407	$	52.02	691,336	$	51.50
TSARs
$25.97 to $35.51	3.17	308,837	$	34.59	308,837	$	34.59
$38.24 to $50.17	3.52	386,471	47.62		263,269	46.82
$54.65 to $78.59	4.06	966,019	60.27		482,156	63.91
	3.77	1,661,327	$	52.55	1,054,262	$	51.05

SARs and TSARs outstanding and exercisable by range of exercise prices

Information regarding the SARs and TSARs outstanding as at December 31, 2019 is as follows:



	Units outstanding at December 31, 2019				Units exercisable at December 31, 2019

Range of exercise prices	Weighted average remaining contractual life (years)	Number of units outstanding	Weighted average exercise price		Number of units exercisable	Weighted average exercise price
SARs
$25.97 to $35.51	3.17	186,980	$	34.59	186,980	$	34.59
$38.24 to $50.17	2.91	191,684	46.39		141,597	45.07
$54.65 to $78.59	2.91	478,743	61.08		362,759	62.73
	2.97	857,407	$	52.02	691,336	$	51.50
TSARs
$25.97 to $35.51	3.17	308,837	$	34.59	308,837	$	34.59
$38.24 to $50.17	3.52	386,471	47.62		263,269	46.82
$54.65 to $78.59	4.06	966,019	60.27		482,156	63.91
	3.77	1,661,327	$	52.55	1,054,262	$	51.05

Weighted average assumptions of outstanding SARs and TSARs

The fair value of each outstanding SARs and TSARs grant was estimated on December 31, 2019 and 2018 using the Black-Scholes option pricing model with the following weighted average assumptions:



	2019			2018
Risk-free interest rate	1.6		%	2.6		%
Expected dividend yield	3.7		%	2.7		%
Expected life of SARs and TSARs (years)	1.2			1.5
Expected volatility	38		%	35		%
Expected forfeitures	0.1		%	0.2		%
Weighted average fair value (USD per share)	$	3.03		$	7.93

Changes in stock options issued

Common shares reserved for outstanding incentive stock options as at December 31, 2019 and 2018 are as follows:



	Number of stock options		Weighted average exercise price
Outstanding at December 31, 2017	262,535		$	45.09
Granted	21,900		54.65
Exercised	(83,114	)	38.89
Cancelled	(3,100	)	57.26
Outstanding at December 31, 2018	198,221		$	48.55
Granted	7,410		57.60
Exercised	(2,700	)	31.73
Cancelled	(2,300	)	52.31
Outstanding at December 31, 2019	200,631		$	49.07

Stock options outstanding and exercisable by range of exercise prices

Information regarding the stock options outstanding as at December 31, 2019 is as follows:



	Options outstanding at December 31, 2019				Options exercisable at December 31, 2019

Range of exercise prices	Weighted average remaining contractual life (years)	Number of stock options outstanding	Weighted average exercise price		Number of stock options exercisable	Weighted average exercise price
Options
$25.97 to $35.51	3.17	53,767	$	34.59	53,767	$	34.59
$38.24 to $50.17	1.96	56,554	43.56		47,751	42.35
$54.65 to $78.59	2.88	90,310	61.14		69,033	62.82
	2.70	200,631	$	49.07	170,551	$	48.19

Number and weighted average remaining contractual life of stock options outstanding and exercisable

Information regarding the stock options outstanding as at December 31, 2019 is as follows:



	Options outstanding at December 31, 2019				Options exercisable at December 31, 2019

Range of exercise prices	Weighted average remaining contractual life (years)	Number of stock options outstanding	Weighted average exercise price		Number of stock options exercisable	Weighted average exercise price
Options
$25.97 to $35.51	3.17	53,767	$	34.59	53,767	$	34.59
$38.24 to $50.17	1.96	56,554	43.56		47,751	42.35
$54.65 to $78.59	2.88	90,310	61.14		69,033	62.82
	2.70	200,631	$	49.07	170,551	$	48.19