Stock-based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Weighted Average Assumptions Used in Estimating Fair Value of Stock Options

The fair value of each stock option grant was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions and resulting weighted-average fair value per share:

	2015			2014			2013
Dividend yield.........................................		2.3	%		1.6	%		1.7	%
Expected volatility......................................		36	%		37	%		38	%
Risk free interest rate.....................................		1.7	%		2.2	%		1.2	%
Expected option life in years................................		7.0			7.0			7.0
Weighted-average fair value per share.........................	$	25.96		$	34.20		$	23.93

Options Outstanding and Option Exercisable

The following table summarizes information concerning options outstanding and options exercisable as of December31, 2015:

	(Shares stated in thousands)
	Options Outstanding						Options Exercisable
			Weighted-
			average
			remaining		Weighted-				Weighted-
	Options		contractual life		average		Options		average
Exercise prices range	Outstanding		(in years)		exercise price		Exercisable		exercise price
$37.85 - $67.87.............................		4,882		2.5	$	51.61		4,857	$	51.53
$68.51 - $70.93.............................		7,499		5.6	$	69.81		4,873	$	69.26
$72.11 - $78.31.............................		8,927		7.0	$	73.56		3,206	$	72.51
$83.88 - $84.93.............................		7,585		4.4	$	84.17		6,514	$	84.21
$88.61 - $114.83............................		12,194		8.0	$	95.48		2,920	$	96.55
		41,087		6.1	$	78.73		22,370	$	73.79

Summary of Stock Option Activity

The following table summarizes stock option activity during the years ended December31, 2015, 2014 and 2013:

	(Shares stated in thousands)
	2015					2014					2013
				Weighted-					Weighted-					Weighted-
				average					average					average
				exercise					exercise					exercise
	Shares			price		Shares			price		Shares			price
Outstanding at beginning of year.............		38,583		$	76.10		41,939		$	70.33		42,059		$	67.77
Granted..............................		7,118		$	86.86		6,105		$	99.04		6,570		$	72.16
Exercised.............................		(2,561	)	$	60.10		(8,269	)	$	64.19		(5,168	)	$	51.73
Forfeited.............................		(2,053	)	$	80.34		(1,192	)	$	73.56		(1,522	)	$	70.57
Outstanding at year-end...................		41,087		$	78.73		38,583		$	76.10		41,939		$	70.33

Restricted Stock Transactions

The following table summarizes information about all restricted stock transactions:

	(Shares stated in thousands)
	2015					2014					2013
				Weighted					Weighted					Weighted
				Average					Average					Average
	Restricted			Grant Date		Restricted			Grant Date		Restricted			Grant Date
	Stock			Fair Value		Stock			Fair Value		Stock			Fair Value
Unvested at beginning of year...............		4,138		$	80.80		4,171		$	76.01		3,566		$	73.62
Granted..............................		1,254		$	82.37		1,341		$	96.08		1,949		$	75.65
Vested...............................		(1,495	)	$	71.30		(1,186	)	$	81.59		(958	)	$	66.98
Forfeited.............................		(326	)	$	83.86		(188	)	$	78.68		(386	)	$	74.53
Unvested at year-end.....................		3,571		$	85.04		4,138		$	80.80		4,171		$	76.01

Assumptions Used in Estimating Fair Value of Purchase Rights under Discounted Stock Purchase Plan

The fair value of the employees’ purchase rights under the DSPP was estimated using the Black-Scholes model with the following assumptions and resulting weighted average fair value per share:

	2015			2014			2013
Dividend yield..........................................		2.3	%		1.6	%		1.7	%
Expected volatility.......................................		27	%		19	%		24	%
Risk free interest rate.....................................		0.2	%		0.1	%		0.1	%
Weighted-average fair value per share..........................	$	12.45		$	12.67		$	9.91

Stock-Based Compensation Expense Recognized in Income

The following summarizes stock-based compensation expense recognized in income:

(Stated in millions)
	2015		2014		2013
Stock options..........................................	$	176	$	177	$	165
Restricted stock.........................................		107		114		110
DSPP...............................................		43		38		40
	$	326	$	329	$	315