Earnings Per Share

12 Months Ended

Dec. 31, 2019

Basic earnings per share is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding. Diluted earnings per share is computed by dividing net income available to common stockholders by the weighted-average number of common shares plus the effect of dilutive potential common shares outstanding during the period. Net income and earnings per share for 2017 include the significant impact of the enactment of the Tax Act discussed further in note 14 to the consolidated financial statements. Net income and earnings per share for 2019 and 2018 reflect a reduction in the U.S. federal statutory tax rate from 35 percent to 21 percent following enactment of the Tax Act. The following table sets forth the computation of basic and diluted earnings per share (shares in thousands):



	Year Ended December 31,
	2019		2018		2017
Numerator:
Net income available to common stockholders	$	1,174	$	1,096	$	1,346
Denominator:
Denominator for basic earnings per share—weighted-average common shares	77,341		82,652		84,599
Effect of dilutive securities:
Employee stock options	114		379		403
Restricted stock units	255		499		560
Denominator for diluted earnings per share—adjusted weighted-average common shares	77,710		83,530		85,562
Basic earnings per share	$	15.18	$	13.26	$	15.91
Diluted earnings per share	$	15.11	$	13.12	$	15.73