Selected Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

	Three Months Ended
	March 31				June 30				September 30				December 31
In millions except per share amounts	2019		2018		2019		2018		2019		2018		2019		2018
Operating revenue	$	3,552	$	3,744	$	3,609	$	3,831	$	3,479	$	3,613	$	3,469	$	3,580
Cost of revenue	2,059		2,181		2,099		2,231		2,007		2,096		2,022		2,096
Operating income	839		903		871		932		868		889		824		860
Net income	597		652		623		666		660		638		641		607
Net income per share:
Basic	$	1.82	$	1.92	$	1.92	$	1.98	$	2.05	$	1.91	$	2.00	$	1.84
Diluted	1.81		1.90		1.91		1.97		2.04		1.90		1.99		1.83