Consolidated Statements of Stockholders' Equity - USD ($)	Common Class A	Common Class B	Additional Paid In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Total
Balance at Dec. 28, 2013	$ 1,626,332	$ 177,195	$ 72,719,592	$ 15,268,209	$ (15,668,055)	$ (43,106)	$ 74,080,167
Balance (in shares) at Dec. 28, 2013	16,263,322	1,771,949
Increase (decrease) in Stockholders' equity
Net income				6,902,531			6,902,531
Unrealized gain (loss) on hedge activity, net of tax						(5,444)	(5,444)
Unrealized holding gain (loss) on investments, net of tax						(17,023)	(17,023)
Cash dividends declared				(826,805)			(826,805)
Exercise of stock options	$ 16,438		394,264				410,702
Exercise of stock options (in shares)	164,382
Issuance of restricted stock	$ 4,859		304,668				309,527
Issuance of restricted stock (in shares)	48,594
Stock-based compensation	$ 2,600		176,150				178,750
Stock-based compensation (in shares)	25,998
Other	$ (17,751)		(1,106,573)		1,124,324
Other (in shares)	(177,518)
Balance at Dec. 27, 2014	$ 1,632,478	$ 177,195	72,488,101	21,343,935	(14,543,731)	(65,573)	81,032,405
Balance (in shares) at Dec. 27, 2014	16,324,778	1,771,949
Increase (decrease) in Stockholders' equity
Net income				12,875,269			12,875,269
Unrealized gain (loss) on hedge activity, net of tax						(2,459)	(2,459)
Unrealized holding gain (loss) on investments, net of tax						(115,482)	(115,482)
Cash dividends declared				(6,435,333)			(6,435,333)
Exercise of stock options	$ 17,943		532,141				550,084
Exercise of stock options (in shares)	179,434
Excess tax benefits from stock-based compensation			63,030				63,030
Issuance of restricted stock	$ 6,889		578,834				585,723
Issuance of restricted stock (in shares)	68,893
Stock-based compensation	$ 2,441		190,059				192,500
Stock-based compensation (in shares)	24,409
Conversion of Class B shares to Class A shares	$ 2,947	$ (2,947)
Conversion of Class B shares to Class A shares (in shares)	29,467	(29,467)
Restricted stock received to satisfy tax obligations					(157,308)		(157,308)
Balance at Dec. 26, 2015	$ 1,662,698	$ 174,248	73,852,165	27,783,871	(14,701,039)	(183,514)	88,588,429
Balance (in shares) at Dec. 26, 2015	16,626,981	1,742,482
Increase (decrease) in Stockholders' equity
Net income				19,037,338			19,037,338
Unrealized gain (loss) on hedge activity, net of tax						12,249	12,249
Unrealized holding gain (loss) on investments, net of tax						77,095	77,095
Cash dividends declared				(6,868,627)			(6,868,627)
Exercise of stock options	$ 13,565		57,261				70,826
Exercise of stock options (in shares)	135,654
Excess tax benefits from stock-based compensation			144,342				144,342
Issuance of restricted stock	$ 10,445		740,009				750,454
Issuance of restricted stock (in shares)	104,446
Stock-based compensation	$ 1,818		186,602				188,420
Stock-based compensation (in shares)	18,182
Conversion of Class B shares to Class A shares	$ 5,437	$ (5,437)
Conversion of Class B shares to Class A shares (in shares)	54,371	(54,371)
Restricted stock received to satisfy tax obligations					(269,177)		(269,177)
Balance at Dec. 31, 2016	$ 1,693,963	$ 168,811	$ 74,980,379	$ 39,952,582	$ (14,970,216)	$ (94,170)	$ 101,731,349
Balance (in shares) at Dec. 31, 2016	16,939,634	1,688,111