Marketable Debt Securities (Tables)

9 Months Ended

Sep. 29, 2012

Investments [Abstract]

Investments of marketable debt securities

Investments of marketable debt securities were comprised of the following (in thousands):

	September 29, 2012
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value(1)
U.S. Treasury securities	$	35,031	$	19	$	—		$	35,050
Corporate bonds	26,870		11		(3		)	26,878
U.S. Agency bonds	15,124		7		—			15,131
Municipal bonds	5,693		—		(2		)	5,691
	$	82,718	$	37	$	(5	)	$	82,750

	December 31, 2011
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value(1)
U.S. Treasury securities	$	30,021	$	41	$	—	$	30,062

Maturities of marketable debt securities

Maturities of marketable debt securities were as follows (in thousands):

	September 29, 2012				December 31, 2011
	Amortized Cost		Fair Value(1)		Amortized Cost		Fair Value(1)
Marketable debt securities – current (due in less than one year)	$	47,216	$	47,232	$	20,004	$	20,020
Marketable debt securities – non-current (due in one to two years)	35,502		35,518		10,017		10,042
	$	82,718	$	82,750	$	30,021	$	30,062