Restructuring Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Jun. 30, 2020
Restructuring costs by type [Abstract]
Severance costs and other benefits	$ 4,688		$ 4,222		$ 12,997
Facility costs	209		244		3,954
Impairment of Intangible Assets, Finite-lived	0		0		1,525
Other Restructuring Costs	148		259		259
Restructuring costs	5,045	$ 0	4,725	$ 0	18,735	$ 14,000
Restructuring costs reserve [Roll Forward]
Restructuring reserve balance	4,101		4,101		4,101	$ 2,403
Restructuring costs incurred			3,422
Cash payments			(1,214)
Operating lease and fixed asset impairments due to restructuring			(510)
Minimum [Member]
Restructuring costs by type [Abstract]
Restructuring and Related Cost, Expected Cost Remaining	1,000		1,000		1,000
Maximum [Member]
Restructuring costs by type [Abstract]
Restructuring and Related Cost, Expected Cost Remaining	1,500		1,500		1,500
Utility and Power Infrastructure [Member]
Restructuring costs by type [Abstract]
Severance costs and other benefits	811		818		2,158
Facility costs	1		5		240
Impairment of Intangible Assets, Finite-lived	0		0		1,150
Restructuring costs	812		823		3,548
Process and Industrial Facilities
Restructuring costs by type [Abstract]
Severance costs and other benefits	3,082		2,590		8,758
Facility costs	134		15		2,770
Impairment of Intangible Assets, Finite-lived	0		0		375
Other Restructuring Costs	148		259		259
Restructuring costs	3,364		2,864		12,162
Storage and Terminal Solutions
Restructuring costs by type [Abstract]
Severance costs and other benefits	640		653		1,000
Facility costs	1		1		721
Restructuring costs	641		654		1,721
Corporate [Member]
Restructuring costs by type [Abstract]
Severance costs and other benefits	155		161		1,081
Facility costs	73		223		223
Restructuring costs	$ 228		$ 384		$ 1,304