Stock-Based Compensation And Employee Benefit Plans (Tables)

12 Months Ended

Mar. 31, 2016

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule Of Assumptions Used In The Black-Scholes Valuation Model

	Stock Option Grants				ESPP
	Year Ended March 31,				Year Ended March 31,
	2015		2014		2016		2015		2014
Risk-free interest rate	1.1 -1.9%		1.6%		0.3 - 0.6%		0.04 - 0.2%		0.1	%
Expected volatility	36 - 40%		37 - 42%		32 - 36%		30 - 35%		36 - 38%
Weighted-average volatility	38	%	37	%	33	%	34	%	38	%
Expected term	4.5 years		4.5 years		6 - 12 months		6 - 12 months		6 - 12 months
Expected dividends	None		None		None		None		None

Schedule Of Assumptions Used In Monte-Carlo Simulation Model

The assumptions used in the Monte-Carlo simulation model to value our market-based restricted stock units were as follows: 

	Year Ended March 31,
	2016		2015		2014
Risk-free interest rate	1.0	%	0.9	%	0.4	%
Expected volatility	14 - 53%		16 - 79%		16 - 58%
Weighted-average volatility	26	%	30	%	31	%
Expected dividends	None		None		None

Schedule Of Stock-Based Compensation Expense By Statement Of Operations

The following table summarizes stock-based compensation expense resulting from stock options, restricted stock units, market-based restricted stock units, and the ESPP included in our Consolidated Statements of Operations (in millions):

	Year Ended March 31,
	2016		2015		2014
Cost of revenue	$	2	$	2	$	2
Research and development	103		82		90
Marketing and sales	24		21		26
General and administrative	49		39		32
Stock-based compensation expense	$	178	$	144	$	150

Summary Of Outstanding And Exercisable Stock Options

The following table summarizes outstanding and exercisable stock options as of March 31, 2016:

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number of Shares (in thousands)	Weighted- Average Remaining Contractual Term  (in years)	Weighted- Average Exercise Prices		Potential Dilution		Number of Shares (in thousands)	Weighted- Average Exercise Prices		Potential Dilution
$11.53 - $23.83	317	3.39	$	19.10	0.1	%	313	$	19.18	0.1	%
26.25 - 26.25	1,000	7.58	26.25		0.3	%	580	26.25		0.2	%
27.49 - 35.70	853	8.21	35.50		0.3	%	343	35.21		0.1	%
36.00 - 59.63	1,108	2.47	47.33		0.4	%	970	48.78		0.3	%
$11.53 - $59.63	3,278	5.61	$	35.09	1.1	%	2,206	$	36.55	0.7	%

Shares Repurchased and Retired

The following table summarizes total shares repurchased during fiscal years 2016 and 2015:

	May 2014 Program			May 2015 Program			February 2016 Program			Total
(In millions)	Shares	Amount		Shares	Amount		Shares	Amount		Shares	Amount
Fiscal Year 2015	8.2	$	337	—	$	—	—	$	—	8.2	$	337
Fiscal Year 2016	1.0	$	57	6.9	$	461	7.8	$	500	15.7	$	1,018

Employee Stock Option [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Disclosure Of Stock-Based Compensation Arrangements By Stock-Based Payment Award

The following table summarizes our stock option activity for the fiscal year ended March 31, 2016:

	Options (in thousands)		Weighted- Average Exercise Prices		Weighted- Average Remaining Contractual Term  (in years)	Aggregate Intrinsic Value (in millions)
Outstanding as of March 31, 2015	4,920		$	37.44
Granted	6		66.08
Exercised	(1,594	)	42.43
Forfeited, cancelled or expired	(54	)	35.61
Outstanding as of March 31, 2016	3,278		$	35.09	5.61	$	101
Vested and expected to vest	3,163		$	35.22	5.53	$	97
Exercisable as of March 31, 2016	2,206		$	36.55	4.46	$	65

Restricted Stock Rights [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Disclosure Of Stock-Based Compensation Arrangements By Stock-Based Payment Award

Each restricted stock right granted reduces the number of shares available for grant by 1.43 shares under our Equity Plan. The following table summarizes our restricted stock rights activity, excluding market-based restricted stock unit activity which is discussed below, for the fiscal year ended March 31, 2016:

	Restricted Stock Rights (in thousands)		Weighted- Average Grant Date Fair Values
Balance as of March 31, 2015	10,855		$	26.20
Granted	3,035		64.40
Vested	(5,809	)	22.65
Forfeited or cancelled	(924	)	35.78
Balance as of March 31, 2016	7,157		$	44.04

Market Based Restricted Stock Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Disclosure Of Stock-Based Compensation Arrangements By Stock-Based Payment Award

The following table summarizes our market-based restricted stock unit activity for the year ended March 31, 2016:

	Market-Based Restricted  Stock Units (in thousands)		Weighted- Average  Grant Date Fair Value
Balance as of March 31, 2015	663		$	31.82
Granted	395		79.81
Vested	(742	)	25.77
Vested above target	371		25.77
Forfeited or cancelled	(51	)	40.10
Balance as of March 31, 2016	636		$	64.49