Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($)	Common Class A [Member]	Common Class B [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Preferred Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Treasury Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] AOCI Attributable to Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance at Mar. 31, 2019									$ 707,000	$ 3,039,000	$ 98,260,000	$ (75,740,000)	$ (18,285,000)	$ 409,504,000
Net Earnings									0	0	0	0	0	1,103,000
Cash dividends declared on preferred stock									0	0	0	0	0	(12,000)
Equity incentive program									0	0	25,000	0	0	0
Purchase treasury stock									0	0	0	(2,744,000)	0	0
Balance (Accounting Standards Update 2016-02 [Member]) at Jun. 29, 2019			$ 0	$ 0	$ 0	$ 0	$ 0	$ (2,019,000)
Balance at Jun. 29, 2019									707,000	3,039,000	98,285,000	(78,484,000)	(18,285,000)	408,576,000
Balance at Mar. 31, 2019									707,000	3,039,000	98,260,000	(75,740,000)	(18,285,000)	409,504,000
Net Earnings															$ 5,738,000
Balance at Sep. 28, 2019									703,000	3,040,000	98,313,000	(84,320,000)	(18,285,000)	413,211,000	412,662,000
Balance at Jun. 29, 2019									707,000	3,039,000	98,285,000	(78,484,000)	(18,285,000)	408,576,000
Net Earnings														4,635,000	4,635,000
Equity incentive program									0	0	25,000	0	0	0
Purchase treasury stock									0	0	0	(5,836,000)	0	0
Preferred stock conversion									(4,000)	1,000	3,000	0	0	0
Balance at Sep. 28, 2019									703,000	3,040,000	98,313,000	(84,320,000)	(18,285,000)	413,211,000	412,662,000
Balance at Mar. 31, 2020									681,000	3,041,000	98,384,000	(88,319,000)	(79,220,000)	459,797,000	394,364,000
Net Earnings									0	0	0	0	0	20,706,000
Cash dividends declared on preferred stock									0	0	0	0	0	(12,000)
Equity incentive program									0	0	28,000	0	0	0
Balance at Jun. 27, 2020									681,000	3,041,000	98,412,000	(88,319,000)	(79,220,000)	480,491,000
Balance at Mar. 31, 2020									681,000	3,041,000	98,384,000	(88,319,000)	(79,220,000)	459,797,000	394,364,000
Net Earnings															38,811,000
Purchase treasury stock	$ (1,163,000)	$ 0
Balance at Sep. 26, 2020									681,000	3,041,000	98,436,000	(89,482,000)	(79,220,000)	498,596,000	432,052,000
Balance at Jun. 27, 2020									681,000	3,041,000	98,412,000	(88,319,000)	(79,220,000)	480,491,000
Net Earnings									0	0	0	0	0	18,105,000	18,105,000
Equity incentive program									0	0	24,000	0	0	0
Purchase treasury stock									0	0	0	(1,163,000)	0	0
Balance at Sep. 26, 2020									$ 681,000	$ 3,041,000	$ 98,436,000	$ (89,482,000)	$ (79,220,000)	$ 498,596,000	$ 432,052,000