Note 4 - Accounts Receivable - Accounts Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Warranty claims	$ 10,427	$ 9,473
Other accounts receivable	20,910	12,753
Less allowance for bad debt and warranty claims	(1,416)	(826)
Total	190,650	183,875
Trade Accounts Receivable From Sale of Vehicles [Member]
Trade receivables	100,013	104,779
Trade Receivable Other Than Vehicles [Member]
Trade receivables	$ 60,716	$ 57,697