Stock-Based Compensation (Tables)

6 Months Ended

Sep. 30, 2012

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

Schedule Of Assumptions Used In The Black-Scholes Valuation Model

The estimated assumptions used in the Black-Scholes valuation model to value our stock option grants were as follows:

	Stock Option Grants								ESPP
	Three Months Ended September 30,				Six Months Ended September 30,				Three Months Ended September 30,
	2012		2011		2012		2011		2012		2011
Risk-free interest rate	0.4 - 1.0%		0.4 - 1.2%		0.4 - 1.0%		0.4 - 1.8%		0.1 - 0.2%		0.1	%
Expected volatility	40 - 45%		41 - 44%		40 - 46%		40 - 44%		41 - 42%		39 - 40%
Weighted-average volatility	42	%	44	%	44	%	43	%	41	%	39	%
Expected term	4.3 years		4.4 years		4.4 years		4.4 years		6 - 12 months		6 - 12 months
Expected dividends	None		None		None		None		None		None

Schedule Of Assumptions Used In Monte-Carlo Simulation Model

	Six Months Ended September 30,
	2012		2011
Risk-free interest rate	0.2 - 0.4%		0.2 - 0.6%
Expected volatility	17 - 116%		14 - 83%
Weighted-average volatility	36	%	35	%
Expected dividends	None		None

Schedule Of Stock-Based Compensation Expense By Statement Of Operations

	Three Months Ended September 30,				Six Months Ended September 30,
	2012		2011		2012		2011
Cost of revenue	$	—	$	—	$	1	$	1
Research and development	27		28		49		51
General and administrative	9		9		18		18
Marketing and sales	8		6		15		11
Stock-based compensation expense	$	44	$	43	$	83	$	81

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

	Options (in thousands)		Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in millions)
Outstanding as of March 31, 2012	9,774		$	34.17
Granted	240		12.97
Exercised	(11	)	13.11
Forfeited, cancelled or expired	(797	)	35.46
Outstanding as of September 30, 2012	9,206		33.54		4.41	$	—
Vested and expected to vest	9,134		33.68		4.37	$	—
Exercisable as of September 30, 2012	8,476		34.90		4.08	$	—

Performance 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

	Performance- Based Restricted Stock Units (in thousands)		Weighted- Average Grant Date Fair Value
Balance as of March 31, 2012	1,421		$	50.35
Vested	(19	)	15.39
Forfeited or cancelled	(55	)	46.48
Balance as of September 30, 2012	1,347		51.00

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

	Restricted Stock Rights (in thousands)		Weighted- Average Grant Date Fair Value
Balance as of March 31, 2012	16,323		$	20.73
Granted	7,938		12.51
Vested	(4,583	)	21.56
Forfeited or cancelled	(993	)	18.86
Balance as of September 30, 2012	18,685		17.13

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

	Market-Based Restricted Stock Units (in thousands)		Weighted- Average Grant Date Fair Value
Balance as of March 31, 2012	520		$	34.77
Granted	670		10.45
Vested	(111	)	34.77
Forfeited or cancelled	(62	)	34.77
Balance as of September 30, 2012	1,017		18.75