Marketable Securities

9 Months Ended

Dec. 26, 2020

The Company’s investments have been classified as available-for-sale securities in accordance with U.S. GAAP. Marketable securities are categorized on the consolidated condensed balance sheet as "Marketable securities", within the short-term or long-term classification, as appropriate.

The following table is a summary of available-for-sale securities at December 26, 2020 (in thousands):


As of December 26, 2020	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value (Net Carrying Amount)
Corporate debt securities	$	347,642	$	5,484	$	(11)	$	353,115
Non-U.S. government securities	12,681		218		—		12,899


Agency discount notes	3,760		6		—		3,766
Total securities	$	364,083	$	5,708	$	(11)	$	369,780

The Company typically invests in highly-rated securities with original maturities generally ranging from one to three years. The Company's specifically identified gross unrealized losses were immaterial related to securities with total amortized costs of approximately $8.3 million at December 26, 2020. There were no securities that had been in a continuous unrealized loss position for more than 12 months as of December 26, 2020. The Company may sell certain of its marketable securities prior to their stated maturities for strategic reasons including, but not limited to, anticipated or actual changes in credit rating and duration management. The Company records an allowance for credit loss when a decline in investment market value is due to credit-related factors. When evaluating an investment for impairment, the Company reviews factors including the length of time and extent to which fair value has been below cost basis, the financial condition of the issuer, changes in market interest rates and whether it is more likely than not the Company will be required to sell the investment before recovery of the investment’s cost basis. As of December 26, 2020, the Company does not consider any of its investments to be impaired.

The following table is a summary of available-for-sale securities at March 28, 2020 (in thousands):


As of March 28, 2020	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value (Net Carrying Amount)
Corporate debt securities	$	286,668	$	1,157	$	(3,993)	$	283,832
Non-U.S. government securities	12,483		260		—		12,743
U.S. Treasury securities	8,839		167		—		9,006


Total securities	$	307,990	$	1,584	$	(3,993)	$	305,581

The Company's specifically identified gross unrealized losses of $4.0 million related to securities with total amortized costs of approximately $172.9 million at March 28, 2020. There were no securities that had been in a continuous unrealized loss position for more than 12 months as of March 28, 2020. As of March 28, 2020, the Company did not consider any of its investments to be impaired.

The cost and estimated fair value of available-for-sale securities by contractual maturities were as follows (in thousands):


	December 26, 2020				March 28, 2020
	Amortized		Estimated		Amortized		Estimated
	Cost		Fair Value		Cost		Fair Value
Within 1 year	$	42,680	$	43,289	$	22,012	$	22,008
After 1 year	321,403		326,491		285,978		283,573
Total	$	364,083	$	369,780	$	307,990	$	305,581