Available-for-sale securities - Summary of Maturities of Available-for-sale Securities (Details) - USD ($) $ in Thousands	Apr. 26, 2020	Jan. 26, 2020
Fair Value
Within 1 year	$ 9,016	$ 10,200
After 1 year through 5 years	465	500
Total available-for-sale securities	9,481	10,700
Amortized Cost
Within 1 year	8,760	8,215
After 1 year through 5 years	759	500
Total available-for-sale securities	$ 9,519	$ 8,715

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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