Inventories, Contracts in Progress and Vehicle Floor Plan Payable (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Inventory [Line Items]
Weighted average interest rate	5.10%	5.80%	5.10%	6.00%
Automotive [Member]
Inventory [Line Items]
Borrowing capacity	$ 60,000,000		$ 60,000,000
Vehicle floor plan payable	50,400,000		50,400,000
Floor plan assistance	$ 800,000		$ 1,200,000
Automotive [Member] | Vehicle Floor Plan Facility [Member]
Inventory [Line Items]
Weighted average interest rate	3.40%		3.50%
London Interbank Offered Rate (LIBOR) [Member] | Automotive [Member] | Vehicle Floor Plan Facility [Member]
Inventory [Line Items]
Applicable interest rate margin			1.15%