Investment in Leasing Operations: Credit Losses (Details) - USD ($)	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 580,600	$ 861,200	$ 711,200
Provisions charged to expense	(79,300)	(78,300)	38,600
Recoveries	(11,800)	21,900	213,500
Deductions for amounts written-off	(219,300)	(224,200)	(102,100)
Balance at end of period	270,200	580,600	$ 861,200
Investment In Leases
Total investment in direct financing and sales-type leases	13,512,300	25,657,400
Allowance for Credit Losses
Total	270,200	580,600
Investment in leases
Investment In Leases
Collectively evaluated for loss potential	13,512,300	25,657,400
Total investment in direct financing and sales-type leases	13,512,300	25,657,400
Allowance for Credit Losses
Collectively evaluated for loss potential	270,200	580,600
Total	$ 270,200	$ 580,600