Investment in Leasing Operations: (Details 4) - Investment in leases - USD ($)	6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 386,000	$ 822,700
Provisions charged to expense	(162,200)	27,800
Recoveries	630,300	88,800
Deductions for amounts written-off	(9,300)
Balance at end of period	$ 844,800	$ 939,300