Investments (Tables)

3 Months Ended

Mar. 28, 2020

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 28, 2020 and December 28, 2019 (in thousands):    

			Gross		Gross
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
March 28, 2020
Money market investments	$	15,815	$	—	$	—	$	15,815
Asset-backed securities		571		—		48		523
Corporate bonds and direct obligations of government agencies		98,287		1,038		1,710		97,615
U.S. Treasury obligations		2,336		136		—		2,472
Total	$	117,009	$	1,174	$	1,758	$	116,425

Schedule of Unrealized Loss on Available-for-Sale Investments

For those available-for-sale investments with unrealized losses at March 28, 2020 and December 28, 2019, 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 28, 2020
Asset-backed securities	$	523	$	48	$	—	$	—	$	523	$	48
Corporate bonds and direct obligations of government agencies		49,348		1,710		—		—		49,348		1,710
Total	$	49,871	$	1,758	$	—	$	—	$	49,871	$	1,758
December 28, 2019
Asset-backed securities	$	571	$	1	$	—	$	—	$	571	$	1
Corporate bonds and direct obligations of government agencies		8,728		41		4,260		3		12,988		44
U.S. Treasury obligations		1,226		5		—		—		1,226		5
Total	$	10,525	$	47	$	4,260	$	3	$	14,785	$	50