Investment in Leasing Operations: (Details 4) (Investment in leases, USD $)	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Investment in leases
Activity in the allowance for credit losses for leasing operations
Balance at beginning of period	$ 822,700	$ 775,800
Provisions charged to expense	38,900	13,800
Recoveries	9,000	21,300
Deductions for amounts written-off		(10,900)
Balance at end of period	$ 870,600	$ 800,000