Investments (Details Textual) - USD ($)	3 Months Ended
	Jul. 02, 2016	Jun. 27, 2015	Apr. 02, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	$ (2,457,000)		$ (2,630,000)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	468,000		530,000
Investments (Textual) [Abstract]
Value of investments to be other-than-temporarily impaired	0
Gross gains realized	453,000	$ 180,000
Gross losses realized	(149,000)	$ 46,000
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	(1,000)		0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0		3,000
Common stock of industrial and other companies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	7,306,000		7,744,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(348,000)		(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		100,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	$ (3,000)		$ (3,000)