Consolidated Statements of Stockholders' Equity and Redeemable Noncontrolling Interest Statement - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Restatement Adjustment	Restatement Adjustment Retained earnings	Restatement Adjustment Accumulated other comprehensive income (loss)
Beginning balance, common stock, shares at Apr. 01, 2017		8,994,968
Beginning balance at Apr. 01, 2017	$ 394,408	$ 90	$ 244,791	$ 148,141	$ 1,386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	61,502	0	0	61,502	0
Reclassification adjustment for net gains realized in income, net	(964)	0	0	0	(964)
Unrealized gain on available-for-sale securities, net	702	$ 0	0	0	702
Stock option exercises and associated tax benefits, shares		49,890
Stock option exercises and associated tax benefits, amount	(915)	$ 0	(915)	0	0
Stock-based compensation	2,321	$ 0	2,321	0	0
Ending balance, common stock, shares at Mar. 31, 2018		9,044,858
Ending balance at Mar. 31, 2018	457,106	$ 90	246,197	209,381	1,438
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting principle | Accounting Standards Update 2016-09						$ 52	$ 52
Cumulative effect of new accounting principle | Accounting Standards Update 2018-02						0	(314)	$ 314
Net income	68,622	0	0	68,622	0
Reclassification adjustment for net gains realized in income, net	59	0	0	0	59
Unrealized gain on available-for-sale securities, net	96	$ 0	0	0	96
Stock option exercises and associated tax benefits, shares		53,462
Stock option exercises and associated tax benefits, amount	(114)	$ 1	(115)	0	0
Stock-based compensation	$ 3,365	$ 0	3,365	0	0
Ending balance, common stock, shares at Mar. 30, 2019	9,098,320	9,098,320
Ending balance at Mar. 30, 2019	$ 529,588	$ 91	249,447	280,078	(28)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting principle | Accounting Standards Update 2016-01						0	1,621	(1,621)
Cumulative effect of new accounting principle | Difference between Revenue Guidance in Effect before and after Topic 606						$ 454	$ 454	$ 0
Net income	75,066	0	0	75,066	0
Reclassification adjustment for net gains realized in income, net	14	0	0	0	14
Unrealized gain on available-for-sale securities, net	104	$ 0	0	0	104
Stock option exercises and associated tax benefits, shares		74,922
Stock option exercises and associated tax benefits, amount	(1,067)	$ 1	(1,068)	0	0
Stock-based compensation	$ 3,881	$ 0	3,881	0	0
Ending balance, common stock, shares at Mar. 28, 2020	9,173,242	9,173,242
Ending balance at Mar. 28, 2020	$ 607,586	$ 92	$ 252,260	$ 355,144	$ 90