Borrowing Facilities (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Line of Credit Facility [Line Items]
Maximum amount of Credit Facility	$ 55,000	$ 75,000
Total remaining available under the working capital, acquisition and warehouse facilities	54,150	72,890
Amount borrowed by the Company under the facility		$ 1,200
Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum amount of Credit Facility	$ 55,000
Line of Credit Facility, expiration date	Jun. 30, 2021	Jun. 30, 2019
Tangible net worth	$ 14,700
Leverage ratio	0.24
Interest Coverage ratio	18.67
Amount borrowed by the Company under the facility	$ 0	$ 0
Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.25%
Credit Facility [Member] | Covenant Requirement [Member]
Line of Credit Facility [Line Items]
Tangible net worth requirement under the Credit Facility	$ 10,000
Maximum [Member] | Credit Facility [Member] | Covenant Requirement [Member]
Line of Credit Facility [Line Items]
Leverage ratio	1.25
Interest Coverage ratio	2