Stock-Based Compensation (Tables)

12 Months Ended

Apr. 30, 2013

Stock-Based Compensation

Schedule of weighted average assumptions used to estimate fair value of stock options granted

	Year Ended April 30,
	2013			2012			2011
Expected term (in years)		6.00			5.46			5.00
Expected volatility		45.94	%		26.75	%		24.72	%
Risk-free interest rate		0.92	%		1.40	%		2.08	%
Expected dividend		—			—			—
Weighted average fair value at grant date	$	8.44		$	8.01		$	6.48

Schedule of stock option plans

	Restated 2006 Plan					2002 Plan					1992 Plan
	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding at April 30, 2010		493,210		$	23.36		405,101		$	3.10		387,000		$	0.48
Options granted		72,500			24.91		—			—		—			—
Options exercised		(17,500	)		22.27		(35,634	)		5.67		(67,427	)		0.41
Options canceled		(12,800	)		27.25		(1,408	)		11.79		—			—
Outstanding at April 30, 2011		535,410			23.51		368,059			2.81		319,573			0.49
Options granted		175,000			29.28		—			—		—			—
Options exercised		(18,200	)		21.88		(43,073	)		2.91		(80,263	)		0.51
Options canceled		—			—		—			—		—			—
Outstanding at April 30, 2012		692,210			25.01		324,986			2.80		239,310			0.49
Options granted		203,000			19.07		—			—		—			—
Options exercised		(3,000	)		20.75		(147,597	)		1.39		(57,741	)		0.38
Options canceled		—			—		—			—		—			—
Outstanding at April 30, 2013		892,210			23.67		177,389			3.98		181,569			0.52
Options exercisable at April 30, 2013		457,310		$	23.72		177,389		$	3.98		181,569		$	0.52

Schedule of the status of the Company's non-vested stock options

Non-vested Options	Options			Weighted Average Grant Date Fair Value
Non-vested at April 30, 2012		375,262		$	7.39
Granted		203,000			8.44
Expired		—			—
Canceled		—			—
Vested		(143,362	)		7.31
Non-vested at April 30, 2013		434,900		$	7.91

Schedule of information concerning outstanding and exercisable options

	Options Outstanding
			Weighted Average Remaining Contractual Life In Years				Options Exercisable
Range of Exercise Prices	As of April 30, 2013				Weighted Average Exercise Price		As of April 30, 2013		Weighted Average Exercise Price
$            0.37		57,415		0.89	$	0.37		57,415	$	0.37
0.59		124,154		6.35		0.59		124,154		0.59
0.78		53,288		1.16		0.78		53,288		0.78
2.13		82,766		2.47		2.13		82,766		2.13
11.79		41,335		3.40		11.79		41,335		11.79
18.07-24.65		620,210		6.61		21.19		373,710		22.21
25.77-32.19		272,000		7.80		29.34		83,600		30.43
$  0.37-32.19		1,251,168		5.97	$	17.52		816,268	$	14.27

Schedule of Company's restricted stock awards

	Restated 2006 Plan
	Shares			Weighted Average Grant Date Fair Value
Unvested stock at April 30, 2012		326,787		$	26.84
Stock granted		163,886			18.30
Stock vested		(94,669	)		26.11
Stock canceled		(12,767	)		25.53
Unvested stock at April 30, 2013		383,237		$	23.32

Schedule of Company's restricted stock units

	Restated 2006 Plan
	Shares			Weighted Average Grant Date Fair Value
Unvested restricted stock units at April 30, 2012		—		$	—
Restricted stock units granted		30,584			24.28
Restricted stock units vested		(14,926	)		24.28
Restricted stock units canceled		(732	)		24.28
Unvested restricted stock units at April 30, 2013		14,926		$	24.28