Common Stock and Stock-Based Incentive Compensation Plans (Tables)

12 Months Ended

Dec. 26, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Common Shares Outstanding

Shares of common stock outstanding were as follows:

	Year Ended
	December 26, 2020	December 28, 2019	December 29, 2018
	(In millions)
Balance, beginning of period	1,170	1,005	967
Common stock issued under employee equity plans	14	20	31
Common stock repurchases for tax withholding on equity awards	(1)	—	—
Issuance of common stock upon warrant exercise	—	75	—
Issuance of common stock to settle convertible debt	28	69	—
Issuance of treasury stock to partially settle debt	—	1	7
Balance, end of period	1,211	1,170	1,005

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

Stock-based compensation expense was allocated in the consolidated statements of operations as follows:

	2020		2019		2018
	(In millions)
Cost of sales	$	6	$	6	$	4
Research and development	173		129		91
Marketing, general, and administrative	95		62		42
Total stock-based compensation expense before income taxes	274		197		137
Income tax benefit	(42)		—		—
Total stock-based compensation expense, net of income taxes	$	232	$	197	$	137

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The weighted-average estimated fair value of employee stock options granted for the years ended December 26, 2020, December 28, 2019 and December 29, 2018 was $38.49, $13.31 and $7.62 per share, respectively, using the following assumptions:

	2020		2019		2018
Expected volatility	57.87	%	52.60% - 56.51%		51.51% - 60.46%
Risk-free interest rate	0.18	%	1.53% - 2.51%		2.20% - 2.83%
Expected dividends	—	%	—	%	—	%
Expected life (in years)	4.3		3.94 - 3.95		3.92 - 3.94

The weighted-average grant date fair values of PRSUs granted during 2020, 2019 and 2018 were $122.95, $50.00 and $21.67, respectively, using the following assumptions:

	2020		2019		2018
Expected volatility	55.74% - 60.10%		60.54% - 62.52%		63.77% - 67.97%
Risk-free interest rate	0.14% - 1.41%		1.56% - 2.49%		2.06% - 2.82%
Expected dividends	—	%	—	%	—	%
Expected term (in years)	2.48 - 3.00		2.48 - 5.00		2.48 - 3.00

Schedule of Share-based Compensation, Stock Options, Activity

The following table summarizes stock option activity and related information:

	Outstanding Number of Shares	Weighted- Average Exercise Price		Aggregate Intrinsic Value		Weighted-Average Remaining Contractual Life (in years)
	(In millions, except share price)
Balance as of December 28, 2019	10	$	7.56
Granted	—	$	84.85
Exercised	(3)	$	3.62
Balance as of December 26, 2020	7	$	12.91	$	589	2.92
Exercisable December 26, 2020	6	$	7.01	$	538	2.43

Schedule of Share-based Compensation, Restricted Stock Units, Activity

The following table summarizes time-based RSU activity and related information:

	Number of Shares	Weighted- Average Fair Value		Aggregate Intrinsic Value		Weighted-Average Remaining Contractual Life (in years)
	(In millions except share price)
Unvested shares as of December 28, 2019	18	$	22.93
Granted	4	$	78.59
Forfeited	(1)	$	30.82
Vested	(9)	$	20.67
Unvested shares as of December 26, 2020	12	$	43.98	$	1,078	1.13

Schedule of Nonvested Performance-based Units Activity

The following table summarizes PRSU activity and related information:

	Number of Shares	Weighted- Average Fair Value		Aggregate Intrinsic Value		Weighted-Average Remaining Contractual Life (in years)
	(In millions except share price)
Unvested shares as of December 28, 2019	3	$	36.13
Granted	1	$	122.95
Forfeited	—	$	45.25
Vested	(1)	$	16.45
Unvested shares as of December 26, 2020	3	$	55.63	$	248	2.25

Schedule of ESPP

The weighted-average grant date fair value for the ESPP during 2020, 2019 and 2018 was $20.97, $9.96 and $4.71 per share, respectively, using the following assumptions:

	2020		2019		2018
Expected volatility	55.16% - 66.53%		48.95% - 67.02%		45.88% - 66.66%
Risk-free interest rate	0.11% - 0.15%		1.58% - 2.46%		2.05% - 2.52%
Expected dividends	—	%	—	%	—	%
Expected term (in years)	0.50		0.50		0.50