Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Details of Grants of Stock-based Compensation

The following table presents stock-based compensation and the income tax benefit recognized during the three and nine months ended September 30, 2015 and 2014:

	Three Months Ended September 30				Nine Months Ended September 30
($ in millions)	2015		2014		2015		2014
Total stock-based compensation	$	3	$	15	$	43	$	53
Income tax benefit recognized	1		5		15		18

The following are the details of grants of stock-based compensation during the nine months ended September 30, 2015 and 2014:

	Nine Months Ended September 30
	2015			2014
Grant Details	Shares	Fair Value		Shares	Fair Value
Stock options	589,350	$	26.94	725,442	$	21.55
Restricted stock units	201,421	$	113.75	256,092	$	90.20
Contingent shares (a)	64,718	$	117.91	77,518	$	93.53

(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 in the nine months ended September 30, 2015 was calculated with the following weighted average assumptions:

Weighted average exercise price	$	118.02
Risk-free interest rate	1.9		%
Expected life of option in years	6.5
Expected dividend yield	2.7		%
Expected volatility	29.2		%