17. Earnings (Loss) per Share

The following table illustrates the computation of basic and diluted earnings (loss) per common share for the three and six months ended June 30, 2018 and 2017:


	Three Months Ended
	June 30, 2018			June 30, 2017
	(In thousands of US dollars, except share data)
Basic and diluted loss per share
Net loss	$	(21,505	)	$	(8,059	)

Basic weighted average common stock outstanding		34,420,654			33,952,574
Basic and diluted loss per share	$	(0.62	)	$	(0.24	)

	Six Months Ended
	June 30, 2018			June 30, 2017
	(In thousands of US dollars, except share data)
Basic Earnings (Loss) per Share
Net income (loss)	$	(18,742	)	$	35,679

Basic weighted average common stock outstanding		34,337,345			33,808,237
Basic earnings (loss) per share	$	(0.55	)	$	1.06
Diluted Earnings (Loss) per Share
Net income (loss)	$	(18,742	)	$	35,679
Add back: Interest expense on Exchangeable Notes	$	—		$	2,542
Net income (loss) allocated to common stockholders	$	(18,742	)	$	38,221

Basic weighted average common stock outstanding		34,337,345			33,808,237
Net effect of dilutive equity awards		—			439,264
Net effect of assumed conversion of 5.0% Exchangeable Notes to common stock		—			9,524,614

Diluted weighted average common stock outstanding		34,337,345			43,772,115
Diluted earnings (loss) per share	$	(0.55	)	$	0.87

The following outstanding instruments were excluded from the computation of diluted earnings (loss) per share, as they have an anti-dilutive effect on the calculation:


	Three Months Ended				Six Months Ended
	June 30, 2018		June 30, 2017		June 30, 2018		June 30, 2017
Options		2,782,874		3,006,377		2,782,874		1,026,605
Restricted Stock Units		499,889		149,495		499,889		—

For the three and six months ended June 30, 2018 and for the three months ended June 30, 2017, 10,448,213 of potential common stock from the assumed conversion of Exchangeable Notes was excluded from the computation of diluted earnings per share as the effect was anti-dilutive for the period.