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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Nature of Business (Details) $ in Thousands								12 Months Ended
Nature of Business (Details) $ in Thousands	Jun. 16, 2017 USD ($)	May 30, 2017 USD ($)	May 26, 2017 USD ($)	Nov. 18, 2016 USD ($)	Jun. 24, 2016 USD ($)	Jan. 29, 2016 USD ($)	Feb. 28, 2015 USD ($)	Dec. 31, 2016 USD ($) segment	Dec. 31, 2017 USD ($) item	Sep. 30, 2015
Nature of Business
Number of reportable segments \| segment								3
Number of joint ventures \| item									2
Number of variable interest entities \| item									2
Capitalized property, plant and equipment								$ 545,783	$ 614,889
Pipe Jacking
Nature of Business
Purchase of property, plant and equipment					$ 13,400
Aevenia
Nature of Business
Amount of purchase of assets and liabilities							$ 22,300
Mueller
Nature of Business
Amount of purchase of assets and liabilities						$ 4,100
Northern
Nature of Business
Amount of purchase of assets and liabilities				$ 6,900
Power
Nature of Business
Number of joint ventures \| item									2
Power \| Northern
Nature of Business
Amount of purchase of assets and liabilities				$ 6,900
Power \| Engineering Assets
Nature of Business
Amount of purchase of assets and liabilities		$ 2,300
Pipeline \| Pipe Jacking
Nature of Business
Purchase of property, plant and equipment					$ 13,400
Pipeline \| Coastal
Nature of Business
Amount of purchase of assets and liabilities	$ 27,500
Utilities \| Aevenia
Nature of Business
Amount of purchase of assets and liabilities							$ 22,300
Utilities \| Mueller
Nature of Business
Amount of purchase of assets and liabilities						$ 4,100
Utilities \| FGC
Nature of Business
Amount of purchase of assets and liabilities			$ 37,700
Blythe
Nature of Business
Ownership percentage										50.00%
Carlsbad
Nature of Business
Ownership percentage									50.00%
Wilmington
Nature of Business
Ownership percentage									50.00%