Investment in Leasing Operations: Leasing Income (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Leasing income
Interest income on direct financing and sales-type leases	$ 979,700	$ 2,028,300	$ 2,108,300	$ 4,210,800
Selling profit (loss) at commencement of sales-type leases	872,700		1,185,900	873,500
Operating lease income	654,500	567,800	1,089,900	1,206,100
Income on sales of equipment under lease	903,600	546,300	4,164,900	1,771,900
Other	63,300	60,600	796,000	296,000
Leasing income	$ 3,473,800	$ 3,203,000	$ 9,345,000	$ 8,358,300