Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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Acquisitions (Aquaterra Acquisition) - Additional Information (Detail) - Aquaterra Corporation [Member] CAD in Millions, $ in Millions			1 Months Ended	12 Months Ended
	Jan. 04, 2016 USD ($)	Jan. 04, 2016 CAD	May 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Percentage of share capital acquired	100.00%
Aggregate purchase price	$ 44.0	CAD 61.2
Acquisition Date	Jan. 04, 2016	Jan. 04, 2016
Payments made by former owners of Aquaterra			$ 0.5
Aggregate purchase price	$ 44.5			$ 44.0
Revenue				61.2
Net income (loss)				1.1
Acquisition related costs				$ 1.3