Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Schedule of computation of basic and diluted earnings per share

The following table shows our computation of basic and diluted earnings per share:

	Year Ended December 31,
(in millions, except per share data)	2017		2016		2015
Net income	$	3,577	$	4,373	$	4,526
Basic weighted average shares outstanding	720		751		797
Dilutive effect of share-based awards	3		4		7
Diluted weighted average shares outstanding	723		755		804
Basic earnings per share	$	4.97	$	5.82	$	5.68
Diluted earnings per share	$	4.95	$	5.79	$	5.63