Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2011

Fair Value Measurements [Abstract]

Fair value measurement of financial assets and liabilities on recurring basis

	As of June 30, 2011
	(In thousands)
	As reflected on
	the unaudited
	balance sheet		Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	6,715	$	6,715	$	—	$	—	$	6,715
Corporate and financial institutions debt		205,589		—		205,589		—		205,589
Auction rate securities		28,053		—		—		28,053		28,053
U.S. government agencies		100,533		—		100,533		—		100,533
U.S. treasury bills		57,976		57,976		—		—		57,976
Municipal bonds		40,545		—		40,545		—		40,545
Foreign currency option contracts designated as hedges		2		—		2		—		2
Foreign currency option contracts not designated as hedges		110		—		110		—		110
Total	$	439,523	$	64,691	$	346,779	$	28,053	$	439,523
Liabilities:
Liability for contingent consideration	$	270,708	$	—	$	—	$	270,708	$	270,708
Convertible senior notes due 2016 (face value $230,000)		157,645		—		271,400		—		271,400
Total	$	428,353	$	—	$	271,400	$	270,708	$	542,108

	As of December 31, 2010
	(In thousands)
	As reflected on
	the balance
	sheet		Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	20,932	$	20,932	$	—	$	—	$	20,932
Corporate and financial institutions debt		197,813		—		197,813		—		197,813
Auction rate securities		31,280		—		2,725		28,555		31,280
U.S. government agencies		99,294		—		99,294		—		99,294
U.S. treasury bills		78,916		78,916		—		—		78,916
Municipal bonds		37,160		—		37,160		—		37,160
Foreign currency option contracts designated as hedges		89		—		89		—		89
Foreign currency option contracts not designated as hedges		188		—		188		—		188
Total	$	465,672	$	99,848	$	337,269	$	28,555	$	465,672
Liabilities:
Liability for contingent consideration	$	253,548	$	—	$	—	$	253,548	$	253,548
Convertible senior notes due 2016 (face value $230,000)		152,701		—		271,768		—	$	271,768
Total	$	406,249	$	—	$	271,768	$	253,548	$	525,316

Summary of changes in fair value of the auction rate securities

	Auction Rate Securities
	Six Months Ended June 30,
	2011			2010
	(In thousands)
Fair value at beginning of period	$	28,555		$	37,174
Redemptions		(700	)		(5,600	)
Transfer to Level 2		—			—
Change in valuation		198			59
Fair value at end of period	$	28,053		$	31,633

Summary of the changes in the fair value of the non-current liability for contingent consideration

	Liability for Contingent Consideration
	Six Months Ended June 30,
	2011		2010
	(In thousands)
Fair value at beginning of period	$	253,458	$	200,528
Payments		—		(40,000	)
Change in valuation		17.250		95,485
Fair value at end of period	$	270,708	$	256,013