Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

Stock-based compensation [Abstract]

Stock-Based Compensation

Information regarding stock-based compensation appears in the table below:

Millions,
for the Three Months Ended March 31,	2015		2014
Stock-based compensation, before tax:
Stock options	$	4	$	6
Retention awards		24		29
Total stock-based compensation, before tax	$	28	$	35
Excess tax benefits from equity compensation plans	$	53	$	60

Stock Options Weight Average Assumptions

The table below shows the annual weighted-average assumptions used for valuation purposes:

Weighted-Average Assumptions	2015		2014
Risk-free interest rate		1.3%		1.6%
Dividend yield		1.8%		2.1%
Expected life (years)		5.1		5.2
Volatility		23.4%		30.0%
Weighted-average grant-date fair value of options granted	$	22.30	$	20.18

Stock Options Activity

A summary of stock option activity during the three months ended March 31, 2015, is presented below:

	Options (thous.)	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value (millions)
Outstanding at January 1, 2015	5,387	$	53.56	5.8 yrs.	$	353
Granted	934		122.85	N/A		N/A
Exercised	(413)		44.38	N/A		N/A
Forfeited or expired	(8)		80.00	N/A		N/A
Outstanding at March 31, 2015	5,900	$	65.14	6.3 yrs.	$	268
Vested or expected to vest at March 31, 2015	5,842	$	64.76	6.2 yrs.	$	268
Options exercisable at March 31, 2015	3,976	$	47.87	4.9 yrs.	$	240

Stock Option Exercises

Additional information regarding stock option exercises appears in the table below:

Millions,
for the Three Months Ended March 31,	2015		2014
Intrinsic value of stock options exercised	$	32	$	34
Cash received from option exercises		14		18
Treasury shares repurchased for employee payroll taxes		(7)		(7)
Tax benefit realized from option exercises		12		13
Aggregate grant-date fair value of stock options vested		19		17

Retention Awards Activity

Changes in our retention awards during the three months ended March 31, 2015, were as follows:

	Shares (thous.)	Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2015	3,403	$	64.39
Granted	519		122.83
Vested	(894)		46.94
Forfeited	(23)		67.31
Nonvested at March 31, 2015	3,005	$	79.65

Performance Retention Awards Present Value Calculation Assumptions

The assumptions used to calculate the present value of estimated future dividends related to the February 2015 grant were as follows:

	2015
Dividend per share per quarter	$	0.55
Risk-free interest rate at date of grant		0.8%

Performance Based Units Activity

Changes in our performance retention awards during the three months ended March 31, 2015, were as follows:

	Shares (thous.)	Weighted-Average Grant-Date Fair Value
Nonvested at January 1, 2015	1,583	$	65.33
Granted	339		117.42
Vested	(580)		54.38
Forfeited	(13)		72.98
Nonvested at March 31, 2015	1,329	$	83.32