Commercial Loans Receivables and Allowance for Loan Loss (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 29, 2019	Mar. 30, 2019	Jun. 30, 2018	Mar. 31, 2018
Receivables [Abstract]
Allowance for loan loss	$ 191	$ 180	$ 113	$ 42
Due days for loans accounted for on a non-accrual basis and accruing loans with principal payments past	90 days or more
Due days for loans on nonaccrual status when interest is past due and remains unpaid	90 days or more
Percentage concentration of commercial loans receivables	10.00%	10.00%