Earnings Per Share

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Earnings Per Share

8. Earnings Per Share

The following table provides a reconciliation between basic and diluted earnings per share:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
Millions, Except Per Share Amounts	2021		2020		2021		2020
Net income	$	1,798	$	1,132	$	3,139	$	2,606
Weighted-average number of shares outstanding:
Basic		658.5		677.7		663.1		681.0
Dilutive effect of stock options		0.8		0.7		0.8		0.8
Dilutive effect of retention shares and units		0.8		0.8		0.8		0.9
Diluted		660.1		679.2		664.7		682.7
Earnings per share – basic	$	2.73	$	1.67	$	4.73	$	3.83
Earnings per share – diluted	$	2.72	$	1.67	$	4.72	$	3.82
Stock options excluded as their inclusion would be anti-dilutive		0.4		1.0		0.3		0.8