Earnings per share attributable to stockholders (Tables)

9 Months Ended

Sep. 30, 2020

Earnings per share attributable to stockholders

Computation of Basic and Diluted Earnings Per Share

	Three months ended					Nine months ended
	September 30, 2020					September 30, 2020
	Net income		WA	Per		Net income		WA	Per
	attributable to		number	share		attributable to		number	share
	stockholders		of shares	amount		stockholders		of shares	amount
Basic	$	45,387	109,018,469	$	0.42	$	121,239	108,887,026	$	1.11
Effect of dilutive securities:
Share units		—	548,859		—		—	519,915		—
Stock options		—	802,390		(0.01)		—	653,771		(0.01)
Diluted	$	45,387	110,369,718	$	0.41	$	121,239	110,060,712	$	1.10

8.    Earnings per share attributable to stockholders (continued)

	Three months ended					Nine months ended
	September 30, 2019					September 30, 2019
	Net income		WA	Per		Net income		WA	Per
	attributable to		number	share		attributable to		number	share
	stockholders		of shares	amount		stockholders		of shares	amount
Basic		25,266	108,003,390		0.23	$	97,466	108,453,525	$	0.90
Effect of dilutive securities:
Share units		—	481,268		—		—	430,175		—
Stock options		—	896,515		—		—	750,495		(0.01)
Diluted	$	25,266	109,381,173	$	0.23	$	97,466	109,634,195	$	0.89