Earnings Per Share

9 Months Ended

Sep. 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				Nine Months Ended
	September 30,				September 30,
Millions, Except Per Share Amounts	2021		2020		2021		2020
Net income	$	1,673	$	1,363	$	4,812	$	3,969
Weighted-average number of shares outstanding:
Basic		648.7		675.0		658.3		679.0
Dilutive effect of stock options		0.8		0.9		0.8		0.8
Dilutive effect of retention shares and units		0.8		0.9		0.8		0.9
Diluted		650.3		676.8		659.9		680.7
Earnings per share – basic	$	2.58	$	2.02	$	7.31	$	5.85
Earnings per share – diluted	$	2.57	$	2.01	$	7.29	$	5.83
Stock options excluded as their inclusion would be anti-dilutive		0.4		0.5		0.3		0.7