Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Cash flows from operating activities:
Net income	$ 19,037,338	$ 12,875,269	$ 6,902,531
Adjustments to reconcile net income to net cash from operating activities:
Depreciation	3,124,435	3,284,313	3,441,281
Amortization and write-off of debt issuance costs	304,920	304,920	304,920
Provision for losses on doubtful receivables	25,314	826	6,880
Deferred income taxes	84,737	332,956	1,530,367
Stock-based compensation expense	938,874	778,223	488,277
Gain on sale of discontinued operations			(127,994)
(Gain) loss on sale of property, plant, and equipment, net	(76,474)	(73,295)	153,236
Changes in operating assets and liabilities
Accounts receivable	4,874,984	(7,109,323)	3,718,386
Inventories	747,421	(2,330,929)	5,727,237
Other current assets	91,395	1,740,455	(2,984,124)
Trade accounts payable	(1,146,851)	(1,007,407)	(6,930,928)
Other current liabilities	1,281,992	970,908	(2,688,508)
Net cash from operating activities	29,288,085	9,766,916	9,541,561
Cash flows from investing activities:
Proceeds from sale of discontinued operations			3,884,656
Proceeds from sale of property, plant, and equipment	120,838	862,435	830,451
Additions to property, plant and equipment	(3,742,392)	(3,891,082)	(4,730,958)
Proceeds from sale of investments	43,000	1,029,000	3,175,591
Purchases of investments	(83,178)	(116,479)	(4,289,298)
Net cash from investing activities	(3,661,732)	(2,116,126)	(1,129,558)
Cash flows from financing activities:
Proceeds from revolving line of credit and other long-term debt		38,570,153
Repayments of revolving line of credit and other long-term debt	(833,333)	(39,236,818)	(666,668)
Payment of cash dividends	(6,764,282)	(1,829,028)	(413,326)
Treasury stock purchased	(269,177)	(157,308)
Proceeds from exercise of stock options	70,826	550,084	410,702
Excess tax benefits from stock-based compensation	144,342	63,030
Net cash from financing activities	(7,651,624)	(2,039,887)	(669,292)
Change in cash and cash equivalents	17,974,729	5,610,903	7,742,711
Cash and cash equivalents, beginning of year	17,247,891	11,636,988	3,894,277
Cash and cash equivalents, end of year	35,222,620	17,247,891	11,636,988
Cash paid (received) during the year for:
Income taxes, net	9,162,334	5,112,973	1,652,889
Interest, net	185,480	(210,076)	247,178
Noncash financing activities:
Common stock dividends declared and payable	$ 5,124,130	$ 5,019,785	$ 413,480