Fair Value Measurements (Tables)

9 Months Ended

Dec. 31, 2012

Fair Value, Assets and Liabilities Measured on Recurring Basis [Abstract]

Schedule of Fair Value, Assets and LIabilities Measured on Recurring Basis

Assets and liabilities measured at fair value on a recurring basis at December 31, 2012 are as follows (amounts in thousands):

	Quoted Prices in Active Markets for  Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant  Unobservable Inputs (Level 3)		Total Balance
Assets
Money market mutual funds	$	50,346	$	—	$	—	$	50,346
Marketable equity securities	4,353		—		—		4,353
Corporate bonds and debt	—		715,068		5,681		720,749
Government agency bonds	—		522,534		—		522,534
Deposit accounts	—		414,947		—		414,947
Municipal bonds	—		25,226		—		25,226
Auction rate securities	—		—		33,810		33,810
Total assets measured at fair value	$	54,699	$	1,677,775	$	39,491	$	1,771,965
Liabilities
Contingent consideration	$	—	$	—	$	16,474	$	16,474
Total liabilities measured at fair value	$	—	$	—	$	16,474	$	16,474

Assets measured at fair value on a recurring basis at March 31, 2012 are as follows (amounts in thousands):

	Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Balance
Money market fund deposits	$	232,219	$	—	$	—	$	232,219
Marketable equity securities	5,264		—		—		5,264
Corporate bonds and debt	—		769,479		4,625		774,104
Government agency bonds	—		342,104		—		342,104
Deposit accounts	—		403,536		—		403,536
Municipal bonds	—		20,122		—		20,122
Auction rate securities	—		—		10,246		10,246
Total assets measured at fair value	$	237,483	$	1,535,241	$	14,871	$	1,787,595

Reconciliation for all assets measured at fair value on a recurring basis

The following tables present a reconciliation for all assets and liabilities measured at fair value on a recurring basis, excluding accrued interest components, using significant unobservable inputs (Level 3) for the nine months ended December 31, 2012, and the year ended March 31, 2012 (amounts in thousands):

Nine months ended December 31, 2012	Auction Rate  Securities			Corporate Debt		Contingent Consideration		Total Gains (Losses)
Balance at March 31, 2012	$	10,246		$	4,625	$	—
Total gains or losses (realized and unrealized):
Included in earnings	(412		)	—		—		$	(412	)
Included in other comprehensive income	186			—		—		186
Purchases, sales, issuances, and settlements, net	(600		)	1,056		—
Acquisition-related	24,390			—		16,474
Balance at December 31, 2012	$	33,810		$	5,681	$	16,474	$	(226	)

Year ended March 31, 2012	Auction Rate Securities			Corporate Debt		Total Gains
Balance at March 31, 2011	$	12,475		$	3,500
Total gains or losses (realized and unrealized):
Included in earnings	271			—		$	271
Purchases, sales, issuances, and settlements, net	(2,500		)	1,125
Balance at March 31, 2012	$	10,246		$	4,625	$	271

Fair Value, by Balance Sheet Grouping

Assets measured at fair value on a recurring basis are presented/classified on the condensed consolidated balance sheets at December 31, 2012 as follows (amounts in thousands):

	Quoted Prices  in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Balance
Cash and cash equivalents	$	50,346	$	414,947	$	—	$	465,293
Short-term investments	—		1,157,010		—		1,157,010
Long-term investments	4,353		105,818		39,491		149,662
Total assets measured at fair value	$	54,699	$	1,677,775	$	39,491	$	1,771,965

Assets measured at fair value on a recurring basis are presented/classified in the consolidated balance sheets at March 31, 2012 as follows (amounts in thousands):

	Quoted Prices in Active Markets for Identical Instruments (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs  (Level 3)		Total Balance
Cash and cash equivalents	$	232,219	$	403,536	$	—	$	635,755
Short-term investments	782		822,472		—		823,254
Long-term investments	4,482		309,233		14,871		328,586
Total assets measured at fair value	$	237,483	$	1,535,241	$	14,871	$	1,787,595