Earnings Per Share Attributable to Stockholders (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share Attributable to Stockholders

Computation of Basic and Diluted Earnings Per Share

	Net income		WA
	attributable to		number	Per share
Year ended December 31, 2019	stockholders		of shares	amount
Basic	$	149,039	108,519,739	$	1.37
Effect of dilutive securities:
Share units		—	458,763		—
Stock options		—	780,621		(0.01)
Diluted	$	149,039	109,759,123	$	1.36

10.   Earnings per share attributable to stockholders (continued)

	Net income		WA
	attributable to		number	Per share
Year ended December 31, 2018	stockholders		of shares	amount
Basic	$	121,479	108,063,349	$	1.12
Effect of dilutive securities:
Share units		—	459,503		—
Stock options		—	865,384		(0.01)
Diluted	$	121,479	109,388,236	$	1.11

	Net income		WA
	attributable to		number	Per share
Year ended December 31, 2017	stockholders		of shares	amount
Basic	$	75,027	107,044,348	$	0.70
Effect of dilutive securities:
Share units		(152)	353,880		—
Stock options		—	714,923		(0.01)
Diluted	$	74,875	108,113,151	$	0.69