Stock Compensation Plans (Tables)

9 Months Ended

Sep. 30, 2015

Stock Compensation Plans [Abstract]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

Stock-based compensation expense for the following periods was:

In millions	Three months ended September 30		Nine months ended September 30
	2015	2014	2015	2014
Restricted stock expense	$12	$7	$32	$26
Tax benefit	(4)	(2)	(10)	(8)
Total stock-based compensation (net of tax)	$8	$5	$22	$18