Fair Value of Financial Assets and Liabilities (Tables)

3 Months Ended

Jul. 31, 2012

Fair Value of Financial Assets and Liabilities [Abstract]

Summary of cash and cash equivalents

The following table summarizes the Company’s cash and cash equivalents as of July 31, 2012 and April 30, 2012:

(in thousands)	July 31, 2012		April 30, 2012
Demand deposit accounts	$	62,698	$	45,361
Money market funds		447		288
U.S. Treasury bills		5,000		7,499
Corporate bonds (U.S. Gov. guaranteed)		—		21,219
Total cash and cash equivalents	$	68,145	$	74,367

Summary of short-term investments

The following table summarizes the Company’s short-term investments as of July 31, 2012:

(in thousands)	Cost		Gross Unrealized Gains (Losses)			Fair Value
Available-for-sale securities:
Certificates of deposit (U.S. Gov. guaranteed)	$	7,354	$	(10	)	$	7,344
U.S. Treasury notes		49,153		(4	)		49,149
Corporate bonds (U.S. Gov. guaranteed)		18,175		(8	)		18,167
Total short-term investments	$	74,682	$	(22	)	$	74,660

Summary of fair value of financial assets and liabilities

The following table summarizes the fair value of the Company’s financial assets and liabilities that were measured on a recurring basis as of July 31, 2012 and April 30, 2012:

	Fair Value Measurements at July 31, 2012								Fair Value Measurements at April 30, 2012
(in thousands)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	447	$	—	$	—	$	447	$	288	$	—	$	—	$	288
U.S. Treasury bills		5,000		—		—		5,000		7,499		—		—		7,499
Corporate bonds (U.S. Gov. guaranteed)		—		—		—		—		21,219		—		—		21,219
Total cash equivalents		5,447		—		—		5,447		29,006		—		—		29,006
Restricted cash		604		—		—		604		500		—		—		500
Short-term investments:
Certificates of deposit (U.S. Gov. guaranteed)		7,344		—		—		7,344		4,496		—		—		4,496
U.S. Treasury notes		49,149		—		—		49,149		28,099		—		—		28,099
Corporate bonds (U.S. Gov. guaranteed)		18,167		—		—		18,167		18,239		—		—		18,239
Total short-term investments		74,660		—		—		74,660		50,834		—		—		50,834
Total assets	$	80,711	$	—	$	—	$	80,711	$	80,340	$	—	$	—	$	80,340