CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME - USD ($)	3 Months Ended		6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015	Jun. 25, 2016	Jun. 27, 2015
CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME
NET INCOME	$ 5,394,300	$ 4,751,400	$ 9,957,200	$ 10,805,700
Unrealized net gains (losses) on marketable securities:
Unrealized holding net gains (losses) arising during period	18,700	(10,000)	34,300	38,700
Reclassification adjustment for net gains included in net income				(2,300)
OTHER COMPREHENSIVE INCOME (LOSS), BEFORE TAX	18,700	(10,000)	34,300	36,400
Unrealized net gains/losses on marketable securities:
Unrealized holding net gains/losses arising during period	(7,000)	3,700	(12,900)	(14,800)
Reclassification adjustment for net gains included in net income				900
INCOME TAX (EXPENSE) BENEFIT RELATED TO ITEMS OF OTHER COMPREHENSIVE INCOME	(7,000)	3,700	(12,900)	(13,900)
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	11,700	(6,300)	21,400	22,500
COMPREHENSIVE INCOME	$ 5,406,000	$ 4,745,100	$ 9,978,600	$ 10,828,200