Investment in Leasing Operations: Credit Losses (Details) - USD ($)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 861,200	$ 711,200	$ 896,000
Provision for credit losses	(78,300)	38,600	9,000
Recoveries	21,900	213,500	8,600
Deductions for amounts written-off	(224,200)	(102,100)	(202,400)
Balance at end of period	580,600	861,200	$ 711,200
Investment In Leases
Total investment in direct financing and sales-type leases	25,657,400
Total investment in direct financing and sales-type leases		39,800,200
Allowance for Credit Losses
Total	580,600
Total		861,200
Investment in leases
Investment In Leases
Collectively evaluated for loss potential	25,657,400	39,800,200
Total investment in direct financing and sales-type leases	25,657,400
Total investment in direct financing and sales-type leases		39,800,200
Allowance for Credit Losses
Collectively evaluated for loss potential	580,600	861,200
Total	$ 580,600
Total		$ 861,200