The Company calculates earnings (loss) per share using the two-class method. The two-class method allocates net income or loss to each class of common stock and participating security according to common dividends declared and participation rights in undistributed earnings. For reporting periods in which a net loss is recorded, net loss is not allocated to participating securities because the holders of such securities bear no contractual obligation to fund or otherwise share in the losses. Participating securities consist of nonvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents.

A summary of the information used in the computation of earnings (loss) per common share follows.

	Three Months Ended
	March 31,
(in thousands, except per share data)	2020			2019
Numerator:
Net income (loss) to common shareholders	$	(111,033	)	$	79,164
Net dividends or income allocated to participating securities - basic and diluted		427			1,337
Net income (loss) allocated to common shareholders - basic and diluted	$	(111,460	)	$	77,827
Denominator:
Weighted-average common shares - basic		87,186			85,688
Dilutive potential common shares		—			112
Weighted-average common shares - diluted		87,186			85,800
Earnings (loss) per common share:
Basic	$	(1.28	)	$	0.91
Diluted	$	(1.28	)	$	0.91

Potential common shares consist of stock options, nonvested performance-based awards, and nonvested restricted share awards deferred under the Company’s nonqualified deferred compensation plan. These potential common shares do not enter into the calculation of diluted earnings per share if the impact would be antidilutive, i.e., increase earnings per share or reduce a loss per share. For reporting periods in which a net loss is recorded, no effect is given to potentially dilutive common shares in the computation of loss per common share as any impact from such shares would be antidilutive. Potentially dilutive common shares with a weighted average of 1,281 were excluded from the calculation of earnings per common share for the three months ended March 31, 2019 as the effect would have been antidilutive.