Share-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2015

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

A summary of stock option activity is as follows:



	Shares (000)		Wtd. Avg. Exercise Price Per Share		Wtd. Avg. Remaining Contractual Term (years)	Aggregate Intrinsic Value (in millions)
Outstanding, January 1, 2013	5,344		$	50
Granted	221		53
Exercised	(2,576	)	43			$	63
Expired or cancelled	(206	)	51
Outstanding, December 31, 2013	2,783		$	57	5.1	$	81
Vested or expected to vest, December 31, 2013	2,769		$	57	4.8
Exercisable, December 31, 2013	2,153		$	58	4.2	$	60
Outstanding, January 1, 2014	2,783		$	57
Granted	204		77
Exercised	(473	)	53			$	13
Expired or cancelled	(30	)	43
Outstanding, December 31, 2014	2,484		$	59	4.7	$	28
Vested or expected to vest, December 31, 2014	2,476		$	59	4.5
Exercisable, December 31, 2014	1,957		$	59	3.7	$	23
Outstanding, January 1, 2015	2,484		$	59
Granted	147		77
Exercised	(1,255	)	56			$	39
Expired or cancelled	(104	)	56
Outstanding, December 31, 2015	1,272		$	64	5.2	$	26
Vested or expected to vest, December 31, 2015	1,267		$	64	5.2
Exercisable, December 31, 2015	911		$	62	4.0	$	20

Schedule of options outstanding and exercisable

Options outstanding and exercisable as of December 31, 2015 are as follows:



	Options Outstanding				Options Exercisable
Exercise Price	Shares (000)	Weighted- Average Remaining Contractual Life (years)	Weighted- Average Exercise Price		Shares (000)	Weighted-Average Exercise Price
$27-$34	44	2.9	$	30	44	$	30
$35-$44	86	6.1	45		54	45
$45-$55	347	5.1	53		273	53
$56-$93	795	5.2	73		540	71
	1,272	5.2	$	64	911	$	62

Assumptions used to estimate fair value of share awards

We estimated the fair value of each stock option on the date of grant using the Black-Scholes option pricing model and the following assumptions:



Year Ended December 31	2015		2014		2013
Average risk-free interest rate	1.6	%	1.8	%	1.1	%
Expected dividend yield	1.5	%	1.2	%	1.7	%
Expected volatility	32.0	%	37.0	%	42.0	%
Expected term (years)	6.0		5.9		5.9

Summary of restricted stock activity

A summary of restricted stock activity is as follows:



	Shares (000)		Wtd. Avg. Price Per Share		Wtd. Avg. Remaining Contractual Term (years)	Aggregate Intrinsic Value (in millions)
Unvested, January 1, 2013	589		$	55	1.7
Granted	192		52
Vested	(90	)	52
Forfeited	(64	)	56
Unvested, December 31, 2013	627		$	54	1.3
Granted	169		$	77
Vested	(283	)	63
Forfeited	(50	)	53
Unvested, December 31, 2014	463		$	57	1.2
Granted	179		$	76
Vested	(217	)	59
Forfeited	(20	)	60
Unvested, December 31, 2015	405		$	64	1.3	$	34

Summary of performance share units detail by grant year

A summary of the performance share units detail by grant year is as follows:



	2013^(a)	2014^(b)	2015
Grant Date(s)	February 14, 2013	February 11, 2014 and May 1, 2014	February 11, 2015


Performance Period (years)	2013	2014-2016	2015-2017
Vesting Date(s)	50% on December 31, 2014 and 2015	100% in February, 2017^(c)	100% in February, 2018^(c)


Payout Levels (in units):
Threshold Award	76,120	94,608	82,298
Target Award	152,240	189,215	164,595
Outstanding Award	304,480	378,430	329,190
Shares Issued in 2015	54,617	—	—
Shares Subject to Holding Period as of December 31, 2015	46,623	—	—

(a) The award achieved 140% of the Target Award level over the performance period. Included in these figures is another award consisting of 7,610 of performance share units that were granted on February 14, 2013 with a separate performance period, performance criteria and vesting date. The performance period was 2013 through 2015, with a vesting date of July 1, 2016. The award achieved 124% of the Target Award level over the performance period.

(b) Included in these figures are 3,046 of performance share units that were granted on October 29, 2014 with a separate performance period, performance criteria and vesting date. The performance period is June 1, 2015 through December 31, 2016, with a vesting date of October 29, 2017.