Description of Business - Purchase Price Accounting (Details) $ in Thousands, € in Millions, NZD in Millions									3 Months Ended		12 Months Ended
	Jul. 01, 2016 NZD	Jul. 01, 2016 USD ($)	Jun. 02, 2016 EUR (€)	Jun. 02, 2016 USD ($)	May 13, 2016 USD ($)	Feb. 18, 2016 USD ($)	Mar. 01, 2015 NZD	Mar. 01, 2015 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 NZD	Dec. 31, 2017 USD ($)	Jul. 01, 2016 USD ($)
Business Acquisition [Line Items]
Payment of contingent consideration										$ 500	$ 500	$ 500	$ 684
Underground Solutions
Business Acquisition [Line Items]
Total consideration recorded						$ 88,370
Payments to acquire businesses						85,000
Discounted value of net operating loss tax assets						5,000
Working capital adjustment						$ 1,600
Fyfe Europe
Business Acquisition [Line Items]
Total consideration recorded					$ 3,000
Payments to acquire businesses					$ 2,800
Contingent payment											200
LMJ
Business Acquisition [Line Items]
Total consideration recorded			€ 2.9	$ 3,235
CSL and BCS
Business Acquisition [Line Items]
Total consideration recorded	NZD 8.9	$ 6,400
Payments to acquire businesses	7.5	5,500
Working capital adjustment	0.2	$ 100
Estimated fair value of earnout consideration	NZD 1.2													NZD 1.0	$ 800	$ 900
Increase (decrease) in contingent consideration liability											$ (100)
Schultz
Business Acquisition [Line Items]
Total consideration recorded							NZD 6.7	$ 7,662
Payments to acquire businesses | NZD							NZD 7.1
Working capital adjustment								400
Deferred contingent consideration								$ 1,000
Payment of contingent consideration									$ 500