Investments (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Oct. 01, 2016	Sep. 26, 2015	Oct. 01, 2016	Sep. 26, 2015	Apr. 02, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	$ (3,729,000)		$ (3,729,000)		$ (2,630,000)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	316,000		316,000		530,000
Investments (Textual) [Abstract]
Value of investments to be other-than-temporarily impaired	0
Gross gains realized	208,000	$ 51,000	661,000	$ 231,000
Gross losses realized	(108,000)	$ (66,000)	(257,000)	$ (112,000)
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0		0		0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0		0		3,000
Common stock of industrial and other companies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	8,428,000		8,428,000		7,744,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	$ (191,000)		$ (191,000)		(409,000)
Common stock of bank trust, insurance, and public utility companies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value					100,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax					$ (3,000)