Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

Share-based Compensation, Activity [Table Text Block]

Stock-based compensation and the income tax benefit recognized during the three and nine months ended September 30, 2020 and 2019 were as follows:

	Three Months Ended September 30		Nine Months Ended September 30
($ in millions)	2020	2019	2020	2019
Stock-based compensation	$14	$9	$29	$28
Income tax benefit recognized	$3	$2	$7	$6

Details of Grants of Stock-based Compensation

Grants of stock-based compensation during the nine months ended September 30, 2020 and 2019 were as follows:

	Nine Months Ended September 30
	2020		2019
Grant Details	Shares	Fair Value	Shares	Fair Value
Stock options	663,485	$21.93	588,870	$22.50
Restricted stock units	203,574	$109.99	233,306	$104.69
Contingent shares (a)	55,319	$119.52	51,850	$109.74

(a) The number of contingent shares represents the target value of the award.

Weighted Average Assumptions Used in Calculating the Fair Value of Stock Option

The fair value of the stock option grants issued during the nine months ended September 30, 2020 was calculated with the following weighted average assumptions:

Weighted average exercise price	$119.52
Risk free interest rate	1.6	%
Expected life of option in years	6.5
Expected dividend yield	1.5	%
Expected volatility	20.0	%