FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Mar. 31, 2013

FAIR VALUE MEASUREMENTS

Schedule of financial assets and liabilities measured at fair value on recurring basis, based on the fair value hierarchy

(In thousands)	March 31, 2013		March 31, 2012
Level 1 — Financial Assets
U.S. Treasury bills	$	—	$	20,018
Money market funds	16,549		—
Total Level 1 Financial Assets	16,549		20,018
Level 2 — Financial Assets
Corporate debentures/bonds	75,572		78,169
Commercial paper	28,974		40,334
Government agency bonds	—		26,582
Money market funds	—		13,698
Certificates of deposit	4,000		5,731
Total Level 2 Financial Assets	108,546		164,514
Total cash equivalents and short-term investments	$	125,095	$	184,532

Schedule of available-for-sale securities

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
2013:
Short-term investments:
Corporate debentures/bonds	$	75,578	$	14	$	(20	)	$	75,572
Commercial paper	28,974		—		—			28,974
Certificates of deposit	4,000		—		—			4,000
Total short-term investments	$	108,552	$	14	$	(20	)	$	108,546
Cash equivalents:
Money market funds	16,549		—		—			16,549
Total cash equivalents	$	16,549	$	—	$	—		$	16,549

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
2012:
Short-term investments:
Corporate debentures/bonds	$	78,176	$	21	$	(28	)	$	78,169
Commercial paper	40,331		3		—			40,334
Government agency bonds	26,573		9		—			26,582
Treasury bills	20,000		18		—			20,018
Certificates of deposit	5,729		2		—			5,731
Total short-term investments	$	170,809	$	53	$	(28	)	$	170,834
Cash equivalents:
Money market funds	13,698		—		—			13,698
Total cash equivalents	$	13,698	$	—	$	—		$	13,698