Basic earnings (loss) per share is based on net income (loss) attributable to the Company’s earnings and is calculated based upon the daily weighted-average number of common shares outstanding during the periods presented. Also, this calculation includes fully vested stock and unit awards that have not yet been issued as common stock. Diluted EPS includes the above, plus unvested stock, unit or option awards granted and vested unexercised stock options, but only to the extent these instruments dilute earnings (loss) per share.

For the year ended December 31, 2019, 2018 and 2017, a total of approximately 8 million, 5 million and 8 million, respectively, of potentially dilutive shares were excluded from the computation of diluted earnings per share due to their antidilutive effect or due to the Company recognizing a net loss for the period.

Basic and diluted earnings (loss) per share follows (in millions, except share data):

	December 31,
	2019			2018			2017
Numerator:
Net income (loss) attributable to the Company	$	(97	)	$	52		$	(52	)
Less: net income attributable to participating securities		—			(1	)		—
Net income (loss) attributable to the Company's stockholders	$	(97	)	$	51		$	(52	)
Denominator:
Weighted-average basic common shares outstanding		108,779,891			108,296,155			107,745,229
Effect of dilutive securities		—			341,489			—
Weighted-average diluted common shares outstanding		108,779,891			108,637,644			107,745,229
Earnings (loss) per share attributable to the Company's stockholders:
Basic	$	(0.89	)	$	0.47		$	(0.48	)
Diluted	$	(0.89	)	$	0.47		$	(0.48	)

ASC Topic 260, “Earnings Per Share,” requires companies with unvested participating securities to utilize a two-class method for the computation of net income attributable to the Company per share. The two-class method requires a portion of net income attributable to the Company to be allocated to participating securities, which are unvested awards of share-based payments with non-forfeitable rights to receive dividends or dividend equivalents, if declared. Net losses are not allocated to nonvested shares in periods that the Company determines that those shares are not obligated to participate in losses. For the periods that the Company recognized net income, net income attributable to the Company allocated to these participating securities was excluded from net income attributable to the Company’s stockholders in the numerator of the earnings per share computation.