Note 9 - Revenue - Disaggregated Revenue by Revenue Source (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 1,536,316	$ 1,315,311	$ 4,308,170	$ 3,788,406
Commercial Vehicle [Member]
Revenue	1,070,868	878,845	2,933,952	2,508,970
Parts [Member]
Revenue	258,513	239,401	760,495	699,823
Commercial Vehicle Repair Service [Member]
Revenue	196,272	187,444	580,810	550,257
Financial Service [Member]
Revenue	3,570	2,628	11,223	7,826
Insurance [Member]
Revenue	2,293	2,425	7,651	7,460
Product and Service, Other [Member]
Revenue	$ 4,800	$ 4,568	$ 14,039	$ 14,070