INVESTMENTS (Tables)

12 Months Ended

Mar. 31, 2013

INVESTMENTS

Schedule of investments

			Gross Unrealized
					Losses
(In thousands)	Amortized Cost		Gains		Less than One Year			Greater than One Year			Estimated Fair Value
March 31, 2013
Short-term investments:
Available-for-sale securities:
U.S. government and agency debt securities	$	102,093	$	29	$	(1	)	$	—		$	102,121
Corporate debt securities		10,946		27		—			—			10,973
International government agency debt securities		10,089		8		(1	)		—			10,096
		123,128		64		(2	)		—			123,190
Money market funds		1,201		—		—			—			1,201
		124,329		64		(2	)		—			124,391
Long-term investments:
Available-for-sale securities:
U.S. government and agency debt securities		60,047		—		(17	)		—			60,030
Corporate debt securities		18,725		—		(26	)		(162	)		18,537
International government agency debt securities		3,060		—		—			—			3,060
		81,832		—		(43	)		(162	)		81,627
Held-to-maturity securities:
Certificates of deposit		1,200		—		—			—			1,200
		83,032		—		(43	)		(162	)		82,827
Total investments	$	207,361	$	64	$	(45	)	$	(162	)	$	207,218
March 31, 2012
Short-term investments:
Available-for-sale securities:
U.S. government and agency debt securities	$	62,925	$	67	$	(17	)	$	—		$	62,975
International government agency debt securities		25,646		22		(2	)		—			25,666
Corporate debt securities		12,324		27		—			—			12,351
		100,895		116		(19	)		—			100,992
Held-to-maturity securities:
Certificates of deposit		4,236		—		—			—			4,236
U.S. government obligations		417		—		—			—			417
		4,653		—		—			—			4,653
Money market funds		1,201		—		—			—			1,201
		106,749		116		(19	)		—			106,846
Long-term investments:
Available-for-sale securities:
U.S. government and agency debt securities		35,493		—		(70	)		—			35,423
International government agency debt securities		10,257		—		(20	)		—			10,237
Corporate debt securities		8,009		—		—			(660	)		7,349
Strategic investments		644		838		—			—			1,482
		54,403		838		(90	)		(660	)		54,491
Held-to-maturity securities:
Certificates of deposit		1,200		—		—			—			1,200
		55,603		838		(90	)		(660	)		55,691
Total investments	$	162,352	$	954	$	(109	)	$	(660	)	$	162,537

Proceeds from the sales and maturities of marketable securities, plus the resulting realized gains and losses

	Year Ended March 31,
(In thousands)	2013		2012		2011
Proceeds from the sales and maturities of marketable securities	$	258,937	$	323,028	$	385,511
Realized gains	$	39	$	47	$	77
Realized losses	$	5	$	11	$	32

The cost and fair value of available-for-sale and held-to-maturity securities by contractual maturity

	Available-for-sale				Held-to-maturity
(In thousands)	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Within 1 year	$	80,388	$	80,399	$	1,200	$	1,200
After 1 year through 5 years		124,572		124,418		—		—
Total	$	204,960	$	204,817	$	1,200	$	1,200