Income taxes - Differences between the actual provision for income taxes and the amounts computed by applying the statutory federal tax rate to income before taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 31, 2018
Differences between the actual (benefit) provision for income taxes and the amounts computed by applying the statutory federal tax rate to income before taxes
Provision computed at federal statutory rate	$ 4,453	$ 4,612	$ 2,114
Permanent differences	1,145	1,230	566
One-time transition tax, net		(5,903)	8,521
Change in valuation allowance	(46)	(116)	211
State income taxes, net of federal benefit	1,062	817	455
Effect of foreign income taxes	(8)	(511)	(351)
Remeasurement of deferred tax balances		303	(24,210)
Other, net	109	(151)	(29)
Total provision (benefit) for income taxes	$ 6,715	$ 281	$ (12,723)