Investment in Leasing Operations: Leasing Income (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 25, 2022	Jun. 26, 2021	Jun. 25, 2022	Jun. 26, 2021
Leasing income
Interest income on direct financing and sales-type leases	$ 205,300	$ 482,800	$ 483,800	$ 1,102,500
Selling profit (loss) at commencement of sales-type leases	34,800	356,300	1,298,000	1,430,000
Operating lease income	528,300	476,500	910,100	960,800
Income on sales of equipment under lease	328,700	1,479,900	932,100	2,225,500
Other	114,900	53,100	459,700	366,800
Leasing income	$ 1,212,000	$ 2,848,600	$ 4,083,700	$ 6,085,600