Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2017

The following table sets forth the assumptions used to determine compensation cost for the market condition component of the PSP plan:



	Twelve Months Ended December 31, 2017
Expected volatility	22.75%-23.39%
Risk-free interest rate	1.10%-1.47%

The following summarizes PSP activity for the three years ending December 31, 2017:



	Share/Units		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2014	7,275,934			$34.98
Granted	1,863,623		53.25
Shares issued	(2,959,160	)	37.09
Forfeited	(322,664	)	53.97
Outstanding at December 31, 2015	5,857,733		38.69
Granted	2,617,982		37.26
Shares issued	(2,316,085	)	43.82
Forfeited	(209,500	)	43.61
Outstanding at December 31, 2016	5,950,130		35.89
Granted	2,163,912		51.78
Shares issued	(1,876,134	)	51.00
Forfeited	(438,024	)	45.96
Outstanding at December 31, 2017	5,799,884			$36.17

The following summarizes the activity of the RSA program for the three years ending December 31, 2017:



	Shares		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2014	114,599			$47.03
Granted	36,300		50.06
Shares issued	(27,365	)	45.35
Forfeited	(3,166	)	50.04
Outstanding at December 31, 2015	120,368		48.24
Granted	117,881		42.81
Shares issued	(59,418	)	47.14
Forfeited	(9,500	)	39.36
Outstanding at December 31, 2016	169,331		45.34
Granted	63,319		57.24
Shares issued	(59,650	)	47.90
Forfeited	(6,700	)	53.53
Outstanding at December 31, 2017	166,300			$48.63

Stock-based compensation expense and related income tax benefits were as follows:



In millions	2017		2016		2015
Total stock-based compensation expense (included in selling and administrative expense)	$	147	$	124	$	107
Income tax benefits related to stock-based compensation	45		34		88