(14) STOCK-BASED COMPENSATION

Valuation Assumptions

We estimate the fair value of share-based payment awards on the date of grant. We recognize compensation costs for stock-based payment awards to employees based on the grant-date fair value using a straight-line approach over the service period for which such awards are expected to vest. For awards with only service conditions that have a graded vesting schedule, we recognize compensation costs on a straight-line basis over the requisite service period for the entire award.

We determine the fair value of our share-based payment awards as follows:

•

Restricted Stock Units, Restricted Stock, and Performance-Based Restricted Stock Units. The fair value of restricted stock units, restricted stock, and performance-based restricted stock units (other than market-based restricted stock units) is determined based on the quoted market price of our common stock on the date of grant. Performance-based restricted stock units include grants made in connection with certain acquisitions.

•

Market-Based Restricted Stock Units. Market-based restricted stock units consist of grants of performance-based restricted stock units to certain members of executive management that vest contingent upon the achievement of pre-determined market and service conditions (referred to herein as “market-based restricted stock units”). The fair value of our market-based restricted stock units is determined using a Monte-Carlo simulation model. Key assumptions for the Monte-Carlo simulation model are the risk-free interest rate, expected volatility, expected dividends and correlation coefficient.

•

Stock Options and Employee Stock Purchase Plan. The fair value of stock options and stock purchase rights granted pursuant to our equity incentive plans and our 2000 Employee Stock Purchase Plan (“ESPP”), respectively, is determined using the Black-Scholes valuation model based on the multiple-award valuation method. Key assumptions of the Black-Scholes valuation model are the risk-free interest rate, expected volatility, expected term and expected dividends.

The determination of the fair value of market-based restricted stock units, stock options and ESPP is affected by assumptions regarding subjective and complex variables. Generally, our assumptions are based on historical information and judgment is required to determine if historical trends may be indicators of future outcomes.

There were no significant stock options granted during the three and six months ended September 30, 2013.

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



	Stock Option Grants				ESPP
	Three Months Ended September 30,		Six Months Ended September 30,		Three Months Ended September 30,
	2014		2014		2014		2013
Risk-free interest rate	1.2 - 1.9%		1.1 - 1.9%		0.04 - 0.1%		0.1	%
Expected volatility	36 - 38%		36 - 40%		34 - 35%		36 - 37%
Weighted-average volatility	37	%	38	%	35	%	37	%
Expected term	4.5		4.5		6 - 12 months		6 - 12 months
Expected dividends	None		None		None		None

There were no market-based restricted stock units granted during the three months ended September 30, 2014 and 2013.

Stock-Based Compensation Expense

Employee stock-based compensation expense recognized during the three and six months ended September 30, 2014 and 2013 was calculated based on awards ultimately expected to vest and has been reduced for estimated forfeitures. In subsequent periods, if actual forfeitures differ from those estimates, an adjustment to stock-based compensation expense will be recognized at that time.

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



	Three Months Ended September 30,				Six Months Ended September 30,
	2014		2013		2014		2013
Cost of revenue	$	1	$	1	$	1	$	1
Research and development	23		23		39		43
Marketing and sales	6		6		10		13
General and administrative	10		8		19		14
Stock-based compensation expense	$	40	$	38	$	69	$	71

We did not recognize any benefit from income taxes related to our stock-based compensation expense recognized during the three and six months ended September 30, 2014 and 2013.

As of September 30, 2014, our total unrecognized compensation cost related to stock options was $21 million and is expected to be recognized over a weighted-average service period of 2.8 years. As of September 30, 2014, our total unrecognized compensation cost related to restricted stock and restricted stock units (collectively referred to as “restricted stock rights”) was $283 million and is expected to be recognized over a weighted-average service period of 1.7 years. Of the $283 million of unrecognized compensation cost, $17 million relates to market-based restricted stock units.

During the three and six months ended September 30, 2014, we recognized $2 million and $14 million, respectively, of tax expense for the excess tax benefits resulting from stock-based compensation deductions; this amount is allocated directly to contributed capital and reported in the financing activities on our Condensed Consolidated Statement of Cash Flows.

Stock Options

The following table summarizes our stock option activity for the six months ended September 30, 2014:



	Options (in thousands)		Weighted- Average Exercise Prices		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in millions)
Outstanding as of March 31, 2014	5,311		$	37.43
Granted	1,244		35.75
Exercised	(291	)	20.51
Forfeited, cancelled or expired	(210	)	49.83
Outstanding as of September 30, 2014	6,054		$	37.47	5.35	$	34
Vested and expected to vest	5,671		$	37.85	5.07	$	32
Exercisable as of September 30, 2014	3,744		$	41.43	2.85	$	22

The aggregate intrinsic value represents the total pre-tax intrinsic value based on our closing stock price as of September 30, 2014, which would have been received by the option holders had all the option holders exercised their options as of that date. The weighted-average grant date fair values of stock options granted during the three and six months ended September 30, 2014 were $12.06 and $12.01, respectively. We issue new common stock from our authorized shares upon the exercise of stock options.

Restricted Stock Rights

The following table summarizes our restricted stock rights activity, excluding performance-based restricted stock unit activity which is discussed below, for the six months ended September 30, 2014:



	Restricted Stock Rights (in thousands)		Weighted- Average Grant Date Fair Values
Balance as of March 31, 2014	13,536		$	19.70
Granted	3,893		35.70
Vested	(4,705	)	19.63
Forfeited or cancelled	(930	)	22.53
Balance as of September 30, 2014	11,794		$	24.79

The weighted-average grant date fair values of restricted stock rights granted during the three and six months ended September 30, 2014 were $36.79 and $35.70 respectively.

Performance-Based Restricted Stock Units

The following table summarizes our performance-based restricted stock unit activity for the six months ended September 30, 2014:



	Performance- Based Restricted Stock Units (in thousands)		Weighted- Average Grant Date Fair Values
Balance as of March 31, 2014	54		$	15.39
Vested	(49	)	15.39
Forfeited or cancelled	(5	)	15.39
Balance as of September 30, 2014	—		—

Market-Based Restricted Stock Units

Our market-based restricted stock units vest contingent upon the achievement of pre-determined market and service conditions. If these market conditions are not met but service conditions are met, the restricted stock units will not vest; however, any compensation expense we have recognized to date will not be reversed. The number of shares of common stock to be received at vesting will range from zero percent to 200 percent of the target number of stock units based on our total stockholder return (“TSR”) relative to the performance of companies in the NASDAQ-100 Index for each measurement period, generally over a three year period. In the table below, we present shares granted at 100 percent of target of the number of stock units that may potentially vest. The maximum number of common shares that could vest is approximately 0.4 million for market-based restricted stock units granted during the six months ended September 30, 2014. As of September 30, 2014, the maximum number of shares that could vest is approximately 1.3 million for market-based restricted stock units outstanding.

The following table summarizes our market-based restricted stock unit activity for the six months ended September 30, 2014:



	Market-Based Restricted Stock Units (in thousands)		Weighted- Average Grant Date Fair Value
Balance as of March 31, 2014	978		$	24.83
Granted	193		46.96
Vested	(671	)	21.45
Vested above target	192		16.80
Forfeited or cancelled	(29	)	33.70
Balance as of September 30, 2014	663		$	31.97

Stock Repurchase Program

In May 2014, a special committee of our Board of Directors, on behalf of the full Board of Directors, authorized a new program to repurchase up to $750 million of our common stock. This new stock repurchase program, which expires on May 31, 2016, supersedes and replaces the stock repurchase authorization approved by our Board of Directors in July 2012. Under this program, we may purchase stock in the open market or through privately-negotiated transactions in accordance with applicable securities laws, including pursuant to pre-arranged stock trading plans. The timing and actual amount of the stock repurchases will depend on several factors including price, capital availability, regulatory requirements, alternative investment opportunities and other market conditions. We are not obligated to repurchase any specific number of shares under this program and it may be modified, suspended or discontinued at any time. During the three and six months ended September 30, 2014, we repurchased approximately 2.6 million and 4.0 million shares of our common stock for approximately $95 million and $145 million, respectively. During the three and six months ended September 30, 2013, we did not repurchase any shares of our common stock.