Investment in Leasing Operations: Credit Losses (Details) - USD ($)	3 Months Ended
	Mar. 26, 2022	Mar. 27, 2021	Dec. 25, 2021
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 63,600	$ 270,200
Provisions for credit losses	(8,900)	(48,700)
Recoveries	1,400
Balance at end of period	56,100	$ 221,500
Investment In Leases
Total investment in direct financing and sales-type leases	2,766,100		$ 3,163,000
Allowance for Credit Losses
Total	56,100		63,600
Investment in leases
Investment In Leases
Collectively evaluated for loss potential	2,766,100		3,163,000
Total investment in direct financing and sales-type leases	2,766,100		3,163,000
Allowance for Credit Losses
Collectively evaluated for loss potential	56,100		63,600
Total	$ 56,100		$ 63,600