Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	$ 166,247	$ 143,483	$ 487,957	$ 445,199
Inter-segment revenue	0	0	0	0
Segment operating income (loss)	27,476	21,488	80,062	64,655
Total assets (at end of period)	582,744	562,138	582,744	562,138	$ 573,052
Capital expenditures	4,902	2,438	14,264	7,740
Depreciation and amortization	6,091	6,724	18,820	20,322
Operating Segments [Member] | Reservoir Description [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	101,442	105,427	310,650	321,129
Inter-segment revenue	54	533	275	1,579
Segment operating income (loss)	14,621	21,274	49,231	60,011
Total assets (at end of period)	315,346	322,222	315,346	322,222
Capital expenditures	2,930	2,020	7,605	6,376
Depreciation and amortization	4,383	4,647	13,531	13,914
Operating Segments [Member] | Production Enhancement [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	64,805	38,056	177,307	124,070
Inter-segment revenue	87	563	537	1,167
Segment operating income (loss)	12,972	118	31,132	4,615
Total assets (at end of period)	207,186	190,479	207,186	190,479
Capital expenditures	1,605	318	5,394	856
Depreciation and amortization	1,190	1,429	3,732	4,518
Corporate & Other [Member]
Segment Reporting Information [Line Items]
Revenue from unaffiliated clients	0	0	0	0
Inter-segment revenue	(141)	(1,096)	(812)	(2,746)
Segment operating income (loss)	(117)	96	(301)	29
Total assets (at end of period)	60,212	49,437	60,212	49,437
Capital expenditures	367	100	1,265	508
Depreciation and amortization	$ 518	$ 648	$ 1,557	$ 1,890