Inventories, Contracts in Progress and Vehicle Floor Plan Payable (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Inventory [Line Items]
Weighted average interest rate	5.10%	5.10%	5.10%	5.70%
Vehicle floor plan payable	$ 25,800,000		$ 25,800,000
Automotive [Member]
Inventory [Line Items]
Borrowing capacity	50,000,000		50,000,000
Vehicle floor plan payable	40,900,000		40,900,000
Floor plan assistance	$ 400,000		$ 1,600,000
Automotive [Member] | Vehicle Floor Plan Facility [Member]
Inventory [Line Items]
Weighted average interest rate	3.40%		3.40%
London Interbank Offered Rate (LIBOR) [Member] | Automotive [Member] | Vehicle Floor Plan Facility [Member]
Inventory [Line Items]
Applicable interest rate margin			1.15%