Note 16 - Segments - Segment Reporting Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from external customers	$ 5,126,142	$ 4,735,940	$ 5,809,847
Interest income	657	713	1,680
Interest expense	2,427	9,727	30,487
Depreciation and amortization	53,354	57,456	55,372
Segment operating income	309,036	154,605	216,405
Segment income from continuing operations before taxes	313,683	151,723	189,523
Segment assets	3,119,977	2,985,393	3,407,329
Goodwill	370,331	292,142	292,142
Expenditures for segment assets	167,177	136,200	293,493
Truck Segment [Member]
Revenues from external customers	5,109,070	4,721,058	5,794,155
Interest income	657	713	1,680
Interest expense	2,119	9,444	30,201
Depreciation and amortization	53,096	57,162	55,036
Segment operating income	307,394	153,841	216,691
Segment income from continuing operations before taxes	312,350	151,222	188,122
Segment assets	3,068,365	2,939,390	3,369,517
Goodwill	367,771	289,582	289,582
Expenditures for segment assets	163,624	135,956	292,980
Other Segments [Member]
Revenues from external customers	17,072	14,882	15,692
Interest expense	308	283	286
Depreciation and amortization	258	294	336
Segment operating income	1,642	764	(286)
Segment income from continuing operations before taxes	1,333	501	1,401
Segment assets	51,612	46,003	37,812
Goodwill	2,560	2,560	2,560
Expenditures for segment assets	$ 3,553	$ 244	$ 513