Investments (Tables)

6 Months Ended

Jun. 28, 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 June 28, 2014 and December 28, 2013 (in thousands):

			Gross		Gross
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
June 28, 2014
Money market investments	$	5,278	$	—	$	—	$	5,278
Asset-backed securities		4,892		8		23		4,877
Corporate bonds and direct obligations of government agencies		73,118		853		128		73,843
U.S. Treasury obligations		19,512		29		7		19,534
Total	$	102,800	$	890	$	158	$	103,532
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 June 28, 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
June 28, 2014
Asset-backed securities	$	1,010	$	2	$	2,469	$	21	$	3,479	$	23
Corporate bonds and direct obligations of government agencies		5,562		7		11,451		121		17,013		128
U.S. Treasury obligations		3,000		—		762		7		3,762		7
Total	$	9,572	$	9	$	14,682	$	149	$	24,254	$	158
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