Acquisitions (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands			12 Months Ended
	Oct. 11, 2016	Jun. 09, 2015	Dec. 31, 2016
Nexus
Business Acquisition [Line Items]
Fair Value	$ 6,200
Estimated Useful Life			3 months
Nexus | Trademarks
Business Acquisition [Line Items]
Fair Value	3,200
Nexus | Technology
Business Acquisition [Line Items]
Fair Value	1,300
Estimated Useful Life			15 years
Nexus | Customer relationships
Business Acquisition [Line Items]
Fair Value	800
Estimated Useful Life			11 years
Nexus | Backlog
Business Acquisition [Line Items]
Fair Value	$ 900
Rough Brothers Incorporated
Business Acquisition [Line Items]
Fair Value		$ 56,392
Rough Brothers Incorporated | Trademarks
Business Acquisition [Line Items]
Fair Value		13,550
Rough Brothers Incorporated | Technology
Business Acquisition [Line Items]
Fair Value		3,550
Rough Brothers Incorporated | Customer relationships
Business Acquisition [Line Items]
Fair Value		32,892
Rough Brothers Incorporated | Non-compete agreements
Business Acquisition [Line Items]
Fair Value		1,300
Rough Brothers Incorporated | Backlog
Business Acquisition [Line Items]
Fair Value		$ 5,100
Rough Brothers Incorporated | Maximum | Technology
Business Acquisition [Line Items]
Estimated Useful Life		15 years
Rough Brothers Incorporated | Maximum | Customer relationships
Business Acquisition [Line Items]
Estimated Useful Life		17 years
Rough Brothers Incorporated | Minimum | Technology
Business Acquisition [Line Items]
Estimated Useful Life		7 years
Rough Brothers Incorporated | Minimum | Customer relationships
Business Acquisition [Line Items]
Estimated Useful Life		11 years
Rough Brothers Incorporated | Minimum | Non-compete agreements
Business Acquisition [Line Items]
Estimated Useful Life		5 years
Rough Brothers Incorporated | Minimum | Backlog
Business Acquisition [Line Items]
Estimated Useful Life		6 months