Stock-based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2017

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:

	2017			2016			2015
Dividend yield		2.3	%		2.7	%		2.3	%
Expected volatility		27	%		30	%		36	%
Risk-free interest rate		2.4	%		1.7	%		1.7	%
Expected option life in years		7.0			7.0			7.0
Weighted-average fair value per share	$	20.85		$	17.45		$	25.96

Options Outstanding and Option Exercisable

The following table summarizes information related to options outstanding and options exercisable as of December 31, 2017:

	(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		5,696		4.8	$	56.17		4,132	$	53.91
$68.51 - $71.06		6,665		4.0	$	69.93		6,008	$	69.82
$72.11 - $79.85		9,107		5.5	$	73.97		7,033	$	73.08
$80.53 - $87.38		15,511		6.1	$	84.01		7,186	$	83.68
$88.61 - $114.83		10,231		6.2	$	95.07		5,960	$	95.32
		47,210		5.6	$	79.13		30,319	$	76.71

Summary of Stock Option Activity

The following table summarizes stock option activity during the years ended December 31, 2017, 2016 and 2015:

	(Shares stated in thousands)
	2017					2016					2015
				Weighted-					Weighted-					Weighted-
				Average					Average					Average
				Exercise					Exercise					Exercise
	Shares			Price		Shares			Price		Shares			Price
Outstanding at beginning of year		46,502		$	78.31		41,087		$	78.73		38,583		$	76.10
Granted		5,024		$	86.55		7,672		$	76.14		7,118		$	86.86
Assumed in Cameron transaction		-		$	-		3,088		$	63.24		-		$	-
Exercised		(1,156	)	$	57.87		(3,357	)	$	60.70		(2,561	)	$	60.10
Forfeited		(3,160	)	$	86.99		(1,988	)	$	84.60		(2,053	)	$	80.34
Outstanding at year-end		47,210		$	79.13		46,502		$	78.31		41,087		$	78.73

Restricted Stock Transactions

The following table summarizes information related to restricted stock transactions:

	(Shares stated in thousands)
	2017					2016					2015
				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		5,112		$	78.31		3,571		$	85.04		4,138		$	80.80
Granted		2,495		$	73.09		1,678		$	68.66		1,254		$	82.37
Assumed in Cameron transaction		-		$	-		1,824		$	72.12		-		$	-
Vested		(1,645	)	$	83.03		(1,720	)	$	72.64		(1,495	)	$	71.30
Forfeited		(534	)	$	80.17		(241	)	$	80.87		(326	)	$	83.86
Unvested at year-end		5,428		$	72.33		5,112		$	78.31		3,571		$	85.04

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:

	2017			2016			2015
Dividend yield		2.7	%		2.7	%		2.3	%
Expected volatility		19	%		25	%		27	%
Risk-free interest rate		1.0	%		0.5	%		0.2	%
Weighted-average fair value per share	$	9.46		$	10.37		$	12.45

Stock-Based Compensation Expense Recognized in Income

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

(Stated in millions)
	2017		2016		2015
Stock options	$	161	$	175	$	176
Restricted stock		148		47		107
DSPP		34		45		43
	$	343	$	267	$	326