UNAUDITED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($)	Total	Preferred Stock	Common Stock	Treasury Stock Amount	Additional Paid in Capital	Retained Earnings
Stockholders’ equity, December 30, 2018 at Dec. 31, 2017	$ 39,134,679	$ 0	$ 87,594	$ 0	$ 37,675,329	$ 1,371,756
Stockholders’ equity, December 31, 2018 (in shares) at Dec. 31, 2017			8,759,376
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	67,029				67,029
Exercise of common stock options and warrants (in shares)			4,589
Exercise of common stock options and warrants	(7,500)		$ 46		(7,546)
Cash dividend declared	(2,189,844)					(2,189,844)
Net income (loss)	2,465,571					2,465,571
Stockholders’ equity, June 30, 2019 at Apr. 01, 2018	39,469,935	0	$ 87,640	0	37,734,812	1,647,483
Stockholders’ equity, March 31, 2019 (in shares) at Apr. 01, 2018			8,763,965
Stockholders’ equity, December 30, 2018 at Dec. 31, 2017	39,134,679	0	$ 87,594	0	37,675,329	1,371,756
Stockholders’ equity, December 31, 2018 (in shares) at Dec. 31, 2017			8,759,376
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Option cancellation agreement	3,335,169
Net income (loss)	7,635,455
Stockholders’ equity, June 30, 2019 at Jul. 01, 2018	60,111,307	0	$ 100,890	0	55,831,282	4,179,135
Stockholders’ equity, March 31, 2019 (in shares) at Jul. 01, 2018			10,089,029
Stockholders’ equity, December 30, 2018 at Apr. 01, 2018	39,469,935	0	$ 87,640	0	37,734,812	1,647,483
Stockholders’ equity, December 31, 2018 (in shares) at Apr. 01, 2018			8,763,965
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	47,807				47,807
Issuance of shares, net of offering costs (in shares)			1,293,750
Issuance of shares, net of offering costs	21,386,013		$ 12,938		21,373,075
Exercise of common stock options and warrants (in shares)			31,314
Exercise of common stock options and warrants	11,069		$ 312		10,757
Option cancellation agreement	(3,335,169)				(3,335,169)
Cash dividend declared	(2,638,232)					(2,638,232)
Net income (loss)	5,169,884					5,169,884
Stockholders’ equity, June 30, 2019 at Jul. 01, 2018	60,111,307	0	$ 100,890	0	55,831,282	4,179,135
Stockholders’ equity, March 31, 2019 (in shares) at Jul. 01, 2018			10,089,029
Stockholders’ equity, December 30, 2018 at Dec. 30, 2018	65,702,013	0	$ 102,273	(24,027)	57,624,379	7,999,388
Stockholders’ equity, December 31, 2018 (in shares) at Dec. 30, 2018			10,227,247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	320,084				320,084
Cancellation of restricted shares (in shares)			(2,250)
Cancellation of restricted shares	0		$ (23)		23
Exercise of common stock options and warrants (in shares)			4,916
Exercise of common stock options and warrants	0		$ 49		(49)
Change in accounting principal - operating leases	(200,607)					(200,607)
Cash dividend declared	(3,068,847)					(3,068,847)
Net income (loss)	2,496,024					2,496,024
Stockholders’ equity, June 30, 2019 at Mar. 31, 2019	65,248,667	0	$ 102,299	(24,027)	57,944,437	7,225,958
Stockholders’ equity, March 31, 2019 (in shares) at Mar. 31, 2019			10,229,913
Stockholders’ equity, December 30, 2018 at Dec. 30, 2018	65,702,013	0	$ 102,273	(24,027)	57,624,379	7,999,388
Stockholders’ equity, December 31, 2018 (in shares) at Dec. 30, 2018			10,227,247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Option cancellation agreement	0
Net income (loss)	6,297,854
Stockholders’ equity, June 30, 2019 at Jun. 30, 2019	66,168,151	0	$ 102,347	(24,027)	58,131,018	7,958,813
Stockholders’ equity, March 31, 2019 (in shares) at Jun. 30, 2019			10,234,718
Stockholders’ equity, December 30, 2018 at Mar. 31, 2019	65,248,667	0	$ 102,299	(24,027)	57,944,437	7,225,958
Stockholders’ equity, December 31, 2018 (in shares) at Mar. 31, 2019			10,229,913
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	186,629				186,629
Exercise of common stock options and warrants (in shares)			4,805
Exercise of common stock options and warrants	0		$ 48		(48)
Cash dividend declared	(3,068,974)					(3,068,974)
Net income (loss)	3,801,829					3,801,829
Stockholders’ equity, June 30, 2019 at Jun. 30, 2019	$ 66,168,151	$ 0	$ 102,347	$ (24,027)	$ 58,131,018	$ 7,958,813
Stockholders’ equity, March 31, 2019 (in shares) at Jun. 30, 2019			10,234,718