Investment in Leasing Operations: Credit Losses (Details) - USD ($)	3 Months Ended
	Apr. 01, 2017	Mar. 26, 2016	Dec. 31, 2016
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 896,000	$ 859,100
Provision for credit losses	(1,400)	(14,400)
Recoveries	7,700	700
Deductions for amounts written-off		(3,800)
Balance at end of period	902,300	$ 841,600
Investment In Leases
Total investment in direct financing and sales-type leases	42,572,400		$ 42,286,700
Allowance for Credit Losses
Total	902,300		896,000
Investment in leases
Investment In Leases
Collectively evaluated for loss potential	42,572,400		42,286,700
Total investment in direct financing and sales-type leases	42,572,400		42,286,700
Allowance for Credit Losses
Collectively evaluated for loss potential	902,300		896,000
Total	$ 902,300		$ 896,000