Description of Business - Contributions to Revenues and Profits Since Acquisitions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill impairment	$ 43,500	$ 43,484	$ 51,512	$ 0
Energy Services
Business Acquisition [Line Items]
Goodwill impairment	$ 33,500	33,527
Schultz and Brinderson
Business Acquisition [Line Items]
Revenues		339,305	305,807	108,233
Net income		(21,917)	$ 13,310	$ 4,838
Schultz and Brinderson | Energy Services
Business Acquisition [Line Items]
Goodwill impairment		33,500
Goodwill, impairment, net of tax		$ 25,700