CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 24, 2021	Dec. 25, 2020	Dec. 24, 2021	Dec. 25, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 32,973	$ (5,060)	$ 93,903	$ 9,412
Net income attributable to non-controlling interests	37	35	112	103
Net income (loss) attributable to Allegro MicroSystems, Inc.	32,936	(5,095)	93,791	9,309
Other comprehensive (loss) income:
Foreign currency translation adjustment	(1,306)	3,972	(4,873)	10,152
Net actuarial loss amortization of net transition obligation and prior service costs related to defined benefit plans, net of tax	0	0	0	(313)
Comprehensive income (loss)	31,630	(1,123)	88,918	19,148
Other comprehensive (income) loss attributable to non-controlling interest	(3)	(10)	61	(34)
Comprehensive income (loss) attributable to Allegro MicroSystems, Inc.	$ 31,627	$ (1,133)	$ 88,979	$ 19,114