The Company provides a dual presentation of its net income (loss) per common share in its consolidated statements of operations: basic net income (loss) per common share (“Basic EPS”) and diluted net income (loss) per common share (“Diluted EPS”).

Basic EPS excludes dilution and is computed by first allocating earnings between common stockholders and holders of non-vested shares of restricted stock. Basic EPS is then determined by dividing the earnings attributable to common stockholders by the weighted average number of common shares outstanding during the period, excluding non-vested shares of restricted stock.

Diluted EPS is based on the weighted average number of common shares outstanding plus the dilutive effect of potential common shares, including stock options, non-vested shares of restricted stock, performance units and restricted stock units. The dilutive effect of stock options, performance units and restricted stock units is determined using the treasury stock method. The dilutive effect of non-vested shares of restricted stock is based on the more dilutive of the treasury stock method or the two-class method, assuming a reallocation of undistributed earnings to common stockholders after considering the dilutive effect of potential common shares other than non-vested shares of restricted stock.

The following table presents information necessary to calculate net income (loss) per share for the years ended December 31, 2019, 2018 and 2017, as well as potentially dilutive securities excluded from the weighted average number of diluted common shares outstanding because their inclusion would have been anti-dilutive (in thousands, except per share amounts):

	2019			2018			2017
BASIC EPS:
Net income (loss)	$	(425,703	)	$	(321,421	)	$	5,910
Adjust for (income) loss attributed to holders of non-vested restricted stock		—			—			(170	)
Income (loss) attributed to common stockholders	$	(425,703	)	$	(321,421	)	$	5,740

Weighted average number of common shares outstanding, excluding non-vested shares of restricted stock		203,039			218,643			198,447

Basic net income (loss) per common share	$	(2.10	)	$	(1.47	)	$	0.03

DILUTED EPS:
Income (loss) attributed to common stockholders	$	(425,703	)	$	(321,421	)	$	5,740

Weighted average number of common shares outstanding, excluding non-vested shares of restricted stock		203,039			218,643			198,447
Add dilutive effect of potential common shares		—			—			1,435
Weighted average number of diluted common shares outstanding		203,039			218,643			199,882

Diluted net income (loss) per common share	$	(2.10	)	$	(1.47	)	$	0.03

Potentially dilutive securities excluded as anti-dilutive		9,195			9,762			3,289