Revenue - Sales by Major Source (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Total Sales	$ 427,433	$ 290,465	$ 796,746	$ 535,262
Oil & Gas Proppants
Disaggregation of Revenue [Line Items]
Total Sales	324,063		636,993
Industrial & Specialty Products
Disaggregation of Revenue [Line Items]
Total Sales	103,370		159,753
Product
Disaggregation of Revenue [Line Items]
Total Sales	345,957	235,891	640,745	439,143
Product | Oil & Gas Proppants
Disaggregation of Revenue [Line Items]
Total Sales	242,587		481,009
Product | Industrial & Specialty Products
Disaggregation of Revenue [Line Items]
Total Sales	103,370		159,736
Service
Disaggregation of Revenue [Line Items]
Total Sales	81,476	$ 54,574	156,001	$ 96,119
Service | Oil & Gas Proppants
Disaggregation of Revenue [Line Items]
Total Sales	81,476		155,984
Service | Industrial & Specialty Products
Disaggregation of Revenue [Line Items]
Total Sales	$ 0		$ 17