Employee Stock and Savings Plans (Tables)

12 Months Ended

Dec. 31, 2018

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

Schedule of assumptions used to determine fair value of stock options granted

The fair values of stock options granted were estimated on the date of grant using a binomial option-pricing model with the following assumptions:

	2018		2017		2016
Expected life (in years)	6.3		6.3		6.4
Average risk-free interest rate	2.2	%	2.2	%	1.9	%
Expected volatility	28.3	%	28.9	%	29.3	%
Expected dividend yield	0	%	0	%	0	%

Summary of stock option activity

A summary of stock option activity is as follows:

	Shares (In thousands)		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (In millions)
Stock options outstanding - December 31, 2017	13,791		$	28.17
Granted	1,283		70.11
Forfeited	(332	)	57.65
Exercised	(2,690	)	18.62
Stock options outstanding - December 31, 2018	12,052		$	33.96	5.2	$	477
Stock options exercisable - December 31, 2018	9,319		$	26.20	4.3	$	441

Summary of restricted stock unit an performance share unit activity

A summary of restricted stock and performance share unit activity is as follows:

	Restricted Stock Units				Performance Share Units
	Shares (In thousands)		Weighted- Average Grant Date Fair Value		Shares (In thousands)		Weighted- Average Grant Date Fair Value
Units - December 31, 2017	1,942		$	44.35	402		$	52.16
Granted	569		71.13		164		75.40
Forfeited	(173	)	54.72		(42	)	55.42
Vested	(517	)	39.03		—		—
Units - December 31, 2018	1,821		$	53.22	524		$	57.60

Schedule of additional information related to stock option and restricted stock unit activity

The table below presents additional information related to stock option and restricted stock unit activity:

(In millions)	2018		2017		2016
Total intrinsic value of stock options exercised	$	147	$	116	$	113
Fair value of restricted stock units vested	37		61		58
Income tax benefit from stock options exercised and restricted stock units vested	43		66		62
Cash received from stock options exercised	29		36		39