Net (Loss) Income per Share - Schedule of Computation of Net (Loss) Income per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 28, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Net Income (Loss)	$ (17,675)	$ 60,850
Basic weighted average shares of common stock (in shares)	193,465,708	191,997,330
Dilutive effect of common stock equivalents (in shares)	0	2,994,576
Diluted weighted average common shares (in shares)	193,465,708	194,991,906
Basic net (loss) income per common share attributable to Allegro MicroSystems, Inc. stockholders	$ (0.09)	$ 0.32
Diluted net (loss) income per common share attributable to Allegro MicroSystems, Inc. stockholders	$ (0.09)	$ 0.31