Fair Value Measurements (Tables)

3 Months Ended

Apr. 01, 2012

Fair Value Disclosures [Abstract]

Fair value measurements

The following table presents the Company’s hierarchy for assets and liabilities measured at fair value on a recurring basis as of April 1, 2012 and January 1, 2012 (in thousands):

	April 1, 2012								January 1, 2012
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets:
Money market funds (cash equivalent)	$	173,640	$	—	$	—	$	173,640	$	166,898	$	—	$	—	$	166,898
Debt securities in government sponsored entities	—		402,699		—		402,699		—		394,039		—		394,039
Corporate debt securities	—		505,429		—		505,429		—		433,382		—		433,382
U.S. Treasury securities	98,041		—		—		98,041		59,169		—		—		59,169
Deferred compensation plan assets	—		12,940		—		12,940		—		10,800		—		10,800
Total assets measured at fair value	$	271,681	$	921,068	$	—	$	1,192,749	$	226,067	$	838,221	$	—	$	1,064,288
Liabilities:
Acquisition related contingent consideration liability	$	—	$	—	$	8,375	$	8,375	$	—	$	—	$	6,638	$	6,638
Deferred compensation liability	—		11,368		—		11,368		—		8,970		—		8,970
Total liabilities measured at fair value	$	—	$	11,368	$	8,375	$	19,743	$	—	$	8,970	$	6,638	$	15,608

Changes in estimated fair value of contingent consideration liabilities

Changes in estimated fair value of contingent consideration liabilities from January 1, 2012 through April 1, 2012 are as follows (in thousands):

	Contingent Consideration Liability (Level 3 Measurement)
Balance as of January 1, 2012	$	6,638
Change in estimated fair value, recorded in acquisition related expense, net	1,737
Balance as of April 1, 2012	$	8,375