Note 13 - Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Intangible Assets and Goodwill [Table Text Block]

December 31,	2019		2018
Transportation	$	19,798	$	19,798
Water		149,127		144,319
Specialty		40,866		40,866
Materials		54,488		54,488
Total goodwill	$	264,279	$	259,471

Schedule of Finite-Lived Intangible Assets [Table Text Block]

			Accumulated
December 31, 2019	Gross Value		Amortization			Net Value
Assets
Customer relationships	$	39,541	$	(16,944	)	$	22,597
Permits		23,959		(12,484	)		11,475
Backlog		10,201		(9,247	)		954
Developed technologies		9,354		(3,752	)		5,602
Trademarks/trade name		8,993		(3,667	)		5,326
Favorable contracts, covenants not to compete and other		5,898		(4,795	)		1,103
Intangible assets		97,946		(50,889	)		47,057
Liabilities
Unfavorable contracts and leases	$	6,773	$	(6,339	)	$	434
Intangible liabilities		6,773		(6,339	)		434
Total net amortized intangible assets	$	91,173	$	(44,550	)	$	46,623

			Accumulated
December 31, 2018	Gross Value		Amortization			Net Value
Assets
Customer relationships	$	38,137	$	(7,640	)	$	30,497
Permits		25,959		(13,494	)		12,465
Backlog		9,713		(5,795	)		3,918
Developed technologies		9,233		(1,384	)		7,849
Trademarks/trade name		9,075		(1,381	)		7,694
Favorable contracts, covenants not to compete and other		5,781		(2,489	)		3,292
Intangible assets		97,898		(32,183	)		65,715
Liabilities
Unfavorable contracts and leases	$	7,000	$	(4,726	)	$	2,274
Intangible liabilities		7,000		(4,726	)		2,274
Total net amortized intangible assets	$	90,898	$	(27,457	)	$	63,441