Contract Liabilities - Activity (Details) - USD ($)	6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Activity of the current and noncurrent deferred franchise revenue
Balance at beginning of period	$ 10,177,300	$ 10,310,200
Franchise and software license fees collected from franchisees, excluding amount earned as revenue during the period	598,400	964,700
Fees earned that were included in the balance at the beginning of the period	(956,300)	(933,200)
Balance at end of period	$ 9,819,400	$ 10,341,700