Contract Liabilities: Activity (Details) - USD ($)	9 Months Ended
	Sep. 25, 2021	Sep. 26, 2020
Activity of the current and noncurrent deferred franchise revenue
Balance at beginning of period	$ 8,708,300	$ 9,575,500
Franchise and software license fees collected from franchisees, excluding amount earned as revenue during the period	1,110,600	656,700
Fees earned that were included in the balance at the beginning of the period	(1,325,400)	(1,287,000)
Balance at end of period	$ 8,493,500	$ 8,945,200