Quarterly Financial Data (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 24, 2016	Jun. 25, 2016	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Quarterly Financial Data (Unaudited):
Total Revenue	$ 17,365,900	$ 16,734,300	$ 16,299,800	$ 16,180,300	$ 6,947,500	$ 15,999,500	$ 15,476,700	$ 21,024,100	$ 66,580,300	$ 69,447,800	$ 61,178,700
Income from Operations	10,501,300	10,438,000	9,323,100	8,038,600	9,690,600	9,341,800	8,084,200	9,974,100	38,301,000	37,090,700	33,059,300
Net Income	$ 6,166,200	$ 6,094,200	$ 5,394,300	$ 4,562,900	$ 5,654,400	$ 5,339,600	$ 4,751,400	$ 6,054,300	$ 22,217,600	$ 21,799,700	$ 20,066,500
Net Income Per Common Share - Basic	$ 1.49	$ 1.48	$ 1.31	$ 1.11	$ 1.37	$ 1.29	$ 1.04	$ 1.21	$ 5.39	$ 4.89	$ 3.96
Net Income Per Common Share - Diluted	$ 1.41	$ 1.41	$ 1.25	$ 1.06	$ 1.31	$ 1.23	$ 1.00	$ 1.17	$ 5.13	$ 4.69	$ 3.85