Borrowing Facilities (Narrative) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Line of Credit Facility [Line Items]
Maximum amount of Credit Facility	$ 55,000	$ 55,000
Total remaining available under the working capital, acquisition and warehouse facilities	53,151	$ 54,150
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	$ 14,000
Leverage ratio	0.23
Interest Coverage ratio	17.38
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%
Minimum [Member] | Credit Facility [Member] | Covenant Requirement [Member]
Line of Credit Facility [Line Items]
Tangible net worth requirement under the Credit Facility	$ 10,000
Interest Coverage ratio	2