Investment in Leasing Operations: Credit Losses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 25, 2021	Dec. 26, 2020
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 63,600	$ 270,200	$ 580,600
Provisions charged to expense	(57,900)	(206,600)	(79,300)
Recoveries	1,400		(11,800)
Deductions for amounts written-off			(219,300)
Balance at end of period	7,100	63,600	$ 270,200
Investment In Leases
Total investment in direct financing and sales-type leases	348,700	3,163,000
Allowance for Credit Losses
Total	7,100	63,600
Investment in leases
Investment In Leases
Collectively evaluated for loss potential	348,700	3,163,000
Total investment in direct financing and sales-type leases	348,700	3,163,000
Allowance for Credit Losses
Collectively evaluated for loss potential	7,100	63,600
Total	$ 7,100	$ 63,600