Investments (Tables)

3 Months Ended

Mar. 29, 2014

Amortized Cost and Fair Value of Available for Sale Investments

The amortized cost and fair values of available-for-sale investments are as follows at March 29, 2014 and December 28, 2013 (in thousands):

			Gross		Gross
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
March 29, 2014
Money market investments	$	2,821	$	—	$	—	$	2,821
Asset-backed securities		5,332		13		56		5,289
Corporate bonds and direct obligations of government agencies		75,816		814		240		76,390
U.S. Treasury obligations		18,514		29		12		18,531
Total	$	102,483	$	856	$	308	$	103,031
December 28, 2013
Money market investments	$	2,499	$	—	$	—	$	2,499
Asset-backed securities		4,350		19		72		4,297
Corporate bonds and direct obligations of government agencies		76,786		783		370		77,199
U.S. Treasury obligations		18,524		31		13		18,542
Total	$	102,159	$	833	$	455	$	102,537

Schedule of Unrealized Loss on Available for Sale Investments

For those available-for-sale investments with unrealized losses at March 29, 2014 and December 28, 2013, the following table summarizes the duration of the unrealized loss (in thousands):

	Less than 12 months				12 months or longer				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
March 29, 2014
Asset-backed securities	$	4,501	$	56	$	—	$	—	$	4,501	$	56
Corporate bonds and direct obligations of government agencies		19,132		240		—		—		19,132		240
U.S. Treasury obligations		2,762		12		—		—		2,762		12
Total	$	26,395	$	308	$	—	$	—	$	26,395	$	308
December 28, 2013
Asset-backed securities	$	3,429	$	72	$	—	$	—	$	3,429	$	72
Corporate bonds and direct obligations of government agencies		22,169		370		—		—		22,169		370
U.S. Treasury obligations		757		13		—		—		757		13
Total	$	26,355	$	455	$	—	$	—	$	26,355	$	455