Investments (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 26, 2015	Dec. 27, 2014	Mar. 28, 2015
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	$ (625,000)		$ (625,000)		$ (913,000)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,009,000		1,009,000		136,000
Investments (Textual) [Abstract]
Value of investments to be other-than-temporarily impaired	0
Gross gains realized	74,000	$ 309,000	305,000	$ 735,000
Gross losses realized	(51,000)	$ (41,000)	(163,000)	$ (120,000)
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		(1,000)
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	10,000		10,000		5,000
Common stock of industrial and other companies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	5,300,000		5,300,000		5,400,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(853,000)		(853,000)		(85,000)
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		100,000
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	$ (3,000)		$ (3,000)		$ (3,000)