Segment Data - Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue, Major Customer [Line Items]
Revenues	$ 216,412	$ 236,262	$ 427,885	$ 463,555
Operating Income (Loss)	10,914	19,143	16,593	32,981
Operating segments | Fluids systems
Revenue, Major Customer [Line Items]
Revenues	172,544	179,738	333,197	357,117
Operating Income (Loss)	12,184	13,327	16,058	23,804
Operating segments | Mats and integrated services
Revenue, Major Customer [Line Items]
Revenues	43,868	56,524	94,688	106,438
Operating Income (Loss)	9,276	14,853	22,814	26,939
Corporate, non-segment | Corporate office
Revenue, Major Customer [Line Items]
Operating Income (Loss)	$ (10,546)	$ (9,037)	$ (22,279)	$ (17,762)