Cash, Cash Equivalents And Marketable Securities (Tables)

12 Months Ended

Mar. 31, 2012

Cash, Cash Equivalents And Marketable Securities [Abstract]

Components Of Marketable Securities

The following is a summary of marketable securities held by NetScout at March 31, 2012 classified as short-term and long-term (in thousands):

	Amortized Cost		Unrealized Gains (Losses)			Fair Value
Type of security:
U.S. government and municipal obligations	$	17,779	$	20		$	17,799
Commercial paper		22,469		0			22,469
Corporate bonds		18,531		(1	)		18,530
Certificates of deposit		3,208		(1	)		3,207
Auction rate securities		17,612		0			17,612
Total short-term marketable securities		79,599		18			79,617
Auction rate securities		1,651		(190	)		1,461
U.S. government and municipal obligations		13,828		8			13,836
Corporate bonds		1,345		2			1,347
Total long-term marketable securities		16,824		(180	)		16,644
Total marketable securities	$	96,423	$	(162	)	$	96,261

The following is a summary of marketable securities held by NetScout at March 31, 2011, classified as short-term and long-term (in thousands):

	Amortized Cost		Unrealized Gains (Losses)			Fair Value
Type of security:
U.S. government and municipal obligations	$	86,670	$	(1	)	$	86,669
Commercial paper		24,111		(1	)		24,110
Corporate bonds		13,364		17			13,381
Certificates of deposit		5,251		12			5,263
Auction rate securities		4,007		0			4,007
Total short-term marketable securities		133,403		27			133,430
Auction rate securities		19,784		(2,302	)		17,482
U.S. government and municipal obligations		8,716		3			8,719
Corporate bonds		1,678		1			1,679
Total long-term marketable securities		30,178		(2,298	)		27,880
Total marketable securities	$	163,581	$	(2,271	)	$	161,310

Contractual Maturities Of Marketable Securities

	March 31, 2012		March 31, 2011
Available-for-sale securities:
Due in 1 year or less	$	79,617	$	133,430
Due after 1 year through 5 years		15,183		10,398
Due after 10 years		1,461		17,482
	$	96,261	$	161,310