Stockholders' Equity (Tables)

12 Months Ended

Apr. 30, 2015

Stock Option Activity

Stock option activity was as follows:

	Number of Options (in thousands)			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Balance as of April 30, 2013		10,829			6.83
Options granted		2,092			8.32
Options exercised		(3,360	)		3.34
Options forfeited		(2,470	)		10.22
Balance as of April 30, 2014		7,091		$	7.74		7.02	$	6,264
Options granted		939			7.31
Options exercised		(1,246	)		4.18
Options forfeited		(1,691	)		9.85
Balance as of April 30, 2015		5,093		$	7.83		7.00	$	1,590
Options vested and expected to vest at April 30, 2015		4,977		$	7.81		6.96	$	1,590
Options vested and exercisable as of April 30, 2015		2,891		$	7.60		5.89	$	1,587

Summary of Stock Options

The summary of stock options as of April 30, 2015 is as follows (number of options in thousands):

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Number of Options		Weighted Average Exercise Price
$0.00 - $4.85		523	$	2.69		3.50		522	$	2.69
$4.86 - $5.75		538		5.14		5.19		387		4.91
$6.28 - $6.58		536		6.47		7.08		383		6.44
$7.08 - $7.36		560		7.22		8.75		147		7.19
$7.39 - $7.50		596		7.42		8.19		270		7.41
$7.53 - $8.10		585		7.63		9.08		27		8.10
$8.58 - $9.46		362		8.90		6.73		265		8.80
$9.51 - $9.51		550		9.51		8.10		264		9.51
$9.52 - $12.00		515		11.59		6.02		378		11.62
$13.95 - $18.67		328		14.89		6.23		248		14.94
$0.00 - $18.67		5,093	$	7.83		7.00		2,891	$	7.60

Restricted Stock Activity

Restricted stock activity was as follows (number of restricted shares in thousands):

	Number of Restricted Shares			Weighted Average Grant Date Fair Value
Unvested balance as of April 30, 2013		1,095		$	10.63
Restricted shares granted		2,629			8.30
Restricted shares vested		(321	)		11.11
Restricted shares forfeited		(426	)		11.18
Unvested balance as of April 30, 2014		2,977		$	8.44
Restricted shares granted		2,305			7.66
Restricted shares vested		(715	)		8.74
Restricted shares forfeited		(1,079	)		8.38
Unvested balance as of April 30, 2015		3,488		$	7.88

Employee Stock Purchase Plan

Assumptions Used to Estimate Fair Value of Options and ESSP Using Black-Scholes Option Pricing Model

The fair value of the Company’s ESPP was estimated at the date of grant using a Black-Scholes option pricing model with the following assumptions:

	Year Ended April 30,
	2015	2014	2013
Expected volatility	36% - 57%	36% - 43%	36% - 37%
Risk-free interest rate	0.05% - 0.11%	0.05% - 0.11%	0.10% - 0.11%
Expected term (in years)	0.5	0.5	0.5
Dividend yield	—	—	—

Stock Options

Assumptions Used to Estimate Fair Value of Options and ESSP Using Black-Scholes Option Pricing Model

The fair value of the Company’s options was estimated at the date of grant using a Black-Scholes option pricing model with the following assumptions:

	Year Ended April 30,
	2015	2014	2013
Expected volatility	43% - 50%	53% - 54%	54% - 55%
Risk-free interest rate	1.46% - 1.93%	1.30% - 2.09%	0.83% - 1.40%
Expected term (in years)	6.00	6.00 - 6.25	5.94 - 6.25
Dividend yield	—	—	—