Fair Value of Financial Instruments (Tables)

3 Months Ended

Jul. 31, 2013

Assets and Liabilities Measured at Fair Value on Recurring Basis

The following tables present our assets and liabilities that we measured at fair value on a recurring basis as of July 31, 2013 and April 30, 2013, respectively, and indicates the fair value hierarchy of the valuation techniques we used to determine such fair value (in thousands):

	July 31, 2013
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance
Cash equivalents	$	45,869	$	—	$	—	$	45,869
Marketable securities		7,466		12,422		—		19,888
Total	$	53,335	$	12,422	$	—	$	65,757

	April 30, 2013
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Balance
Cash equivalents	$	37,716	$	—	$	—	$	37,716
Marketable securities		11,215		13,548		—		24,763
Total	$	48,931	$	13,548	$	—	$	62,479

Held to Maturity Investments Which are Not Recorded at Fair Value

These investments consisted of the following at July 31, 2013 and April 30, 2013 (in thousands):

	July 31, 2013
	Carrying value		Unrealized Gain		Unrealized Loss		Fair value
Held-to-maturity:
Certificates of Deposit	$	—	$	—	$	—	$	—
Tax-exempt state and municipal bonds		25		—		—		25
	$	25	$	—	$	—	$	25

	April 30, 2013
	Carrying value		Unrealized Gain		Unrealized Loss		Fair value
Held-to-maturity:
Certificates of Deposit	$	—	$	—	$	—	$	—
Tax-exempt state and municipal bonds		226		1		—		227
	$	226	$	1	$	—	$	227

Contractual Maturities of Debt Securities Classified as Held to Maturity

The contractual maturities of debt securities classified as held to maturity at July 31, 2013 and April 30, 2013 were as follows (in thousands):

	July 31, 2013		April 30, 2013
Due within one year	$	25	$	226
Due within two years		—		—
Due within three years		—		—
Due after three years		—		—
	$	25	$	226