Short-Term Investments (Tables)

9 Months Ended

Sep. 27, 2013

Cash and Cash Equivalents [Abstract]

Summary of Short-Term Investments

The following table summarizes the Company’s short-term investments (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
As of September 27, 2013
State, municipal and local government agencies bonds	$	36,195	$	41	$	(3	)	$	36,233
Corporate bonds	32,376		16		(11		)	32,381
Commercial paper	3,348		—		—			3,348
U.S. federal government bonds	4,001		3		—			4,004
Total short-term investments	$	75,920	$	60	$	(14	)	$	75,966
As of December 31, 2012
Certificates of deposit	$	1,603	$	—	$	—		$	1,603
State, municipal and local government agencies bonds	59,009		45		(4		)	59,050
Corporate bonds	31,568		4		(10		)	31,562
Commercial paper	10,287		1		—			10,288
U.S. federal government bonds	2,003		—		—			2,003
Total short-term investments	$	104,470	$	50	$	(14	)	$	104,506

Maturities of Short-Term Investments

The following table summarizes the maturities of the Company’s short-term investments (in thousands):

	September 27, 2013		December 31, 2012
Less than one year	$	50,782	$	76,779
Due in 1 - 2 years	25,184		27,727
Total short-term investments	$	75,966	$	104,506