Fair Value Measurements (Tables)

6 Months Ended

Sep. 30, 2013

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 September 30, 2013 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	$	49,949	$	—	$	—	$	49,949
Corporate bonds and debt	—		791,543		6,190		797,733
Government agency bonds	—		776,032		—		776,032
Deposit accounts	—		294,253		—		294,253
Municipal bonds	—		53,771		—		53,771
Auction rate securities	—		—		9,829		9,829
Total assets measured at fair value	$	49,949	$	1,915,599	$	16,019	$	1,981,567
Liabilities
Contingent consideration	$	—	$	—	$	1,022	$	1,022
Total liabilities measured at fair value	$	—	$	—	$	1,022	$	1,022

Assets measured at fair value on a recurring basis at March 31, 2013 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 fund deposits	$	100,878	$	—	$	—	$	100,878
Marketable equity securities	5,509		—		—		5,509
Corporate bonds and debt	—		678,932		6,190		685,122
Government agency bonds	—		558,153		—		558,153
Deposit accounts	—		427,456		—		427,456
Municipal bonds	—		25,138		—		25,138
Auction rate securities	—		—		33,791		33,791
Total assets measured at fair value	$	106,387	$	1,689,679	$	39,981	$	1,836,047
Liabilities
Contingent consideration	$	—	$	—	$	19,100	$	19,100
Total liabilities measured at fair value	$	—	$	—	$	19,100	$	19,100

Reconciliation of assets and liabilities 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 six months ended September 30, 2013, and the year ended March 31, 2013 (amounts in thousands):

Six months ended September 30, 2013	Auction Rate Securities			Corporate Debt		Contingent Consideration			Total Gains (Losses)
Balance at March 31, 2013	$	33,791		$	6,190	$	(19,100	)	$	—
Total gains or losses (realized and unrealized):
Included in earnings	1,105			—		(1,392		)	(287		)
Included in other comprehensive income	(332		)	—		—			(332		)
Purchases, sales, issuances, and settlements, net	(24,735		)	—		19,470			—
Balance at September 30, 2013	$	9,829		$	6,190	$	(1,022	)	$	(619	)

Year ended March 31, 2013	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		)	—		(4,400		)	$	(4,813	)
Included in other comprehensive income	332			—		—			332
Purchases, sales, issuances, and settlements, net	(650		)	1,565		—			—
Acquisition-related	24,275			—		(14,700		)	—
Balance at March 31, 2013	$	33,791		$	6,190	$	(19,100	)	$	(4,481	)

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 September 30, 2013 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
Cash and cash equivalents	$	49,949	$	294,253	$	—	$	344,202
Short-term investments	—		807,709		—		807,709
Long-term investments	—		813,637		16,019		829,656
Total assets measured at fair value	$	49,949	$	1,915,599	$	16,019	$	1,981,567

Assets measured at fair value on a recurring basis are presented/classified in the consolidated balance sheets at March 31, 2013 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
Cash and cash equivalents	$	100,878	$	427,456	$	—	$	528,334
Short-term investments	—		1,050,263		—		1,050,263
Long-term investments	5,509		211,960		39,981		257,450
Total assets measured at fair value	$	106,387	$	1,689,679	$	39,981	$	1,836,047