Loss Per Share

12 Months Ended

Dec. 31, 2020

Basic earnings per share is computed by dividing net earnings for the period by the weighted average number of shares of common stock outstanding during the period. Diluted earnings per share is computed by dividing net earnings for the period by the weighted average number of shares of common stock and potentially dilutive common stock outstanding during the period. The dilutive effect of outstanding options and equity incentive awards is reflected in diluted earnings per share by application of the treasury stock method. In periods when the Company has a net loss, equity incentive awards are excluded from the denominator in the Company's calculation of earnings per share as their inclusion would have an antidilutive effect. The following table sets forth the computation of basic and diluted loss per share for the year ended December 31, 2020, 2019 and 2018.


(U.S. dollars in millions, except per share amounts)	Year Ended December 31
	2020		2019		2018
Numerator:
Basic and diluted:
Net loss attributable to common shareholders	$	(545)	$	(500)	$	(276)


Denominator:
Basic: Weighted average number of shares outstanding (in millions)	111.56		101.62		87.16
Diluted: Weighted-average number of shares outstanding, assuming dilution (in millions)	111.56		101.62		87.16


Basic loss per share	$	(4.89)	$	(4.92)	$	(3.17)
Diluted loss per share	$	(4.89)	$	(4.92)	$	(3.17)

To avoid antidilutive effects, the Company excluded equity incentive awards of 817,733, 287,326 and 446,821 shares for the year ended December 31, 2020, 2019 and 2018, respectively.

The Company may settle the conversions of the Notes in cash, shares of the Company's common stock or any combination thereof at its election. For the Notes, the number of shares of the Company's common stock issuable at the conversion price of $22.3125 per share would be 9,277,305 shares if the Company elected to settle the conversion wholly in shares. See Note 5, Debt. Due to anti-dilutive effects, the Company excluded potential convertible shares due to the Notes of 9,277,305 and 5,515,548 shares for the year ended December 31, 2020 and 2019, respectively, and zero for the year ended December 31, 2018 from the diluted loss per share calculations.