Background, Organization, and Summary of Significant Accounting Policies - Schedule of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 343,023
Foreign currency translation adjustment	(2,826)
Goodwill, ending balance	340,197
Natural Gas Operations
Goodwill [Roll Forward]
Goodwill, beginning balance	10,095
Foreign currency translation adjustment	0
Goodwill, ending balance	10,095
Utility Infrastructure Services
Goodwill [Roll Forward]
Goodwill, beginning balance	332,928
Foreign currency translation adjustment	(2,826)
Goodwill, ending balance	$ 330,102