Stock Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Stock-based Compensation Expense

Stock-based compensation expense for the following periods were:

In millions	Three months ended June 30				Six months ended June 30
	2020		2019		2020		2019
Restricted stock units	$	13	$	22	$	32	$	42
Stock options	6		2		10		4
Employee stock purchase plan	1		1		3		2
Stock-based compensation expense	20		25		45		48
Tax benefit	(2)		(4)		(5)		(7)
Stock-based compensation expense (net of tax)	$	18	$	21	$	40	$	41

Schedule of Valuation Assumptions Used To Estimate Fair Value of Stock Options

The table below details the assumptions used in determining the fair value of the option grants.

	Six months ended June 30
	2020			2019
Dividend yield	$	—		$	—
Risk-free interest rate	1.44		%	2.50		%
Expected volatility	33.51		%	34.79		%
Expected holding period (years)	3.7			3.9