Business Combinations - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
EPMH
Business Acquisition [Line Items]
Sales	$ 1,659,775	$ 1,454,070
Net (loss) income	$ (179,220)	$ 116,899
Basic (loss) earnings per share (in dollars per share)	$ (2.34)	$ 1.44
Diluted (loss) earnings per share (in dollars per share)	$ (2.34)	$ 1.43
MS Sand
Business Acquisition [Line Items]
Sales		$ 1,287,202
Net (loss) income		$ 143,604
Basic (loss) earnings per share (in dollars per share)		$ 1.77
Diluted (loss) earnings per share (in dollars per share)		$ 1.75