SHARE-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Summary of the components and classification of share-based compensation expense

The components and classification of share-based compensation expense related to stock options and RSUs for the years 2019, 2018 and 2017 were as follows:

(in millions)	2019		2018		2017
Stock options	$	21	$	23	$	18
RSUs	81		64		69
Share-based compensation expense	$	102	$	87	$	87
Research and development expenses	$	9	$	9	$	8
Selling, general and administrative expenses	93		78		79
Share-based compensation expense	$	102	$	87	$	87

Schedule of weighted-average assumption as of the date of grant using the Black Scholes option-pricing model

The fair values of all stock options granted for the years 2019, 2018 and 2017 were estimated as of the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	2019		2018		2017
Expected stock option life (years)	3.0		3.0		3.0
Expected volatility	46.5	%	54.0	%	67.3	%
Risk-free interest rate	2.5	%	2.7	%	1.8	%
Expected dividend yield	—	%	—	%	—	%

Summary of stock option activity

The following table summarizes stock option activity during 2019:

(in millions, except per share amounts)	Options		Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Outstanding, January 1, 2019	5.9		$	27.88
Granted	1.7		$	23.19
Exercised	(0.3	)	$	16.03
Expired or forfeited	(0.2	)	$	37.27
Outstanding, December 31, 2019	7.1		$	26.99	7.5	$	61
Vested and expected to vest, December 31, 2019	6.7		$	27.43	7.4	$	57
Vested and exercisable, December 31, 2019	3.6		$	34.27	6.5	$	24

Summary of non-vested time-based RSU activity

The following table summarizes non-vested time-based RSU activity during 2019:

(in millions, except per share amounts)	Time-Based RSUs		Weighted- Average Grant-Date Fair Value Per Share
Non-vested, January 1, 2019	5.8		$	18.29
Granted	3.1		$	24.13
Vested	(1.9	)	$	17.88
Forfeited	(0.9	)	$	23.77
Non-vested, December 31, 2019	6.1		$	20.54

Schedule of assumptions used to calculate the fair values of performance-based RSUs

The fair values of TSR performance-based RSUs granted during 2019, 2018 and 2017 were estimated with the following assumptions:

	2019	2018	2017
Contractual term (years)	3.0	3.0	3.0
Expected Company share volatility	46.5%	54.2%	67.2% - 77.2%
Risk-free interest rate	2.5%	2.7%	1.7% - 1.8%

Summary of non-vested performance-based RSU activity

The following table summarizes non-vested performance-based RSU activity during 2019:

(in millions, except per share amounts)	Performance-based RSUs		Weighted- Average Grant-Date Fair Value Per Share
Non-vested, January 1, 2019	1.5		$	34.06
Granted	1.0		$	29.52
Vested	(0.3	)	$	48.42
Forfeited	(0.2	)	$	91.76
Non-vested, December 31, 2019	2.0		$	25.80