Note 19 - Reportable Segment Information - Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Total revenue	$ 768,286	$ 834,671	$ 1,315,872	$ 1,401,003
Range of reduction in gross profit from each project, net	78,480	98,232	128,255	151,944
Depreciation, depletion and amortization	12,399	15,210	26,526	27,165
Segment assets	2,291,332	2,478,898	2,291,332	2,478,898	$ 2,494,927
Constructions [Member]
Total revenue	632,260	713,425	1,107,195	1,220,396
Range of reduction in gross profit from each project, net	61,166	76,267	109,358	129,036
Depreciation, depletion and amortization	5,595	8,864	13,389	15,482
Materials [Member]
Total revenue	136,026	121,246	208,677	180,607
Range of reduction in gross profit from each project, net	17,314	21,965	18,897	22,908
Depreciation, depletion and amortization	6,804	6,346	13,137	11,683
Operating Segments [Member]
Total revenue	812,704	881,394	1,377,193	1,459,717
Segment assets	727,082	704,700	727,082	704,700
Operating Segments [Member] | Constructions [Member]
Total revenue	632,260	713,425	1,107,195	1,220,396
Segment assets	369,160	372,952	369,160	372,952
Operating Segments [Member] | Materials [Member]
Total revenue	180,444	167,969	269,998	239,321
Segment assets	357,922	331,748	357,922	331,748
Consolidation, Eliminations [Member]
Total revenue	(44,418)	(46,723)	(61,321)	(58,714)
Consolidation, Eliminations [Member] | Constructions [Member]
Total revenue	0	0	0	0
Consolidation, Eliminations [Member] | Materials [Member]
Total revenue	$ (44,418)	$ (46,723)	$ (61,321)	$ (58,714)