Investments (Tables)

3 Months Ended

Mar. 27, 2021

Amortized Cost and Fair Value of Available-for-Sale Investments

			Gross		Gross
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
March 27, 2021
Money market investments	$	14,731	$	—	$	—	$	14,731
Asset-backed securities		566		—		11		555
Corporate bonds and direct obligations of government agencies		102,075		2,950		144		104,881
U.S. Treasury obligations		2,339		102		—		2,441
Total	$	119,711	$	3,052	$	155	$	122,608
December 26, 2020
Money market investments	$	17,867	$	—	$	—	$	17,867
Asset-backed securities		567		—		26		541
Corporate bonds and direct obligations of government agencies		98,241		3,551		72		101,720
U.S. Treasury obligations		2,338		125		—		2,463
Total	$	119,013	$	3,676	$	98	$	122,591

Schedule of Unrealized Loss on Available-for-Sale Investments

For those available-for-sale investments with unrealized losses at March 27, 2021 and December 26, 2020, 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 27, 2021
Asset-backed securities	$	—	$	—	$	555	$	11	$	555	$	11
Corporate bonds and direct obligations of government agencies		8,596		123		1,255		21		9,851		144
Total	$	8,596	$	123	$	1,810	$	32	$	10,406	$	155
December 26, 2020
Asset-backed securities	$	541	$	26	$	—	$	—	$	541	$	26
Corporate bonds and direct obligations of government agencies		2,681		72		—		—		2,681		72
Total	$	3,222	$	98	$	—	$	—	$	3,222	$	98