Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenue, Net	$ 182,723	$ 197,265	$ 203,889	$ 213,643	$ 278,622	$ 276,135	$ 267,562	$ 262,903	$ 797,520	$ 1,085,222	$ 1,073,508
Segment Reporting Information, Intersegment Revenue									0	0	0
Income Before Interest Expense and Taxes	23,642	$ 46,818	$ 47,893	$ 42,717	90,450	$ 89,120	$ 84,134	$ 82,827	161,070	346,531	333,419
Assets	625,258				673,325				625,258	673,325	659,364
Payments to Acquire Property, Plant, and Equipment									22,797	36,586	35,416
Depreciation and amortization									27,457	26,696	25,471
Operating Segment Reservoir Description [Member]
Segment Reporting Information [Line Items]
Revenue, Net									473,372	518,974	522,251
Segment Reporting Information, Intersegment Revenue									8,674	10,387	3,432
Income Before Interest Expense and Taxes									111,032	143,624	146,338
Assets	326,182				319,325				326,182	319,325	321,106
Payments to Acquire Property, Plant, and Equipment									17,849	21,371	22,601
Depreciation and amortization									16,778	15,816	14,898
Operating Segment Production Enhancement [Member]
Segment Reporting Information [Line Items]
Revenue, Net									267,224	467,577	452,415
Segment Reporting Information, Intersegment Revenue									1,837	2,459	3,140
Income Before Interest Expense and Taxes									35,027	165,204	154,715
Assets	210,214				257,135				210,214	257,135	255,764
Payments to Acquire Property, Plant, and Equipment									3,292	7,990	7,124
Depreciation and amortization									6,611	7,509	7,745
Operating Segment Reservoir Management [Member]
Segment Reporting Information [Line Items]
Revenue, Net									56,924	98,671	98,842
Segment Reporting Information, Intersegment Revenue									248	366	1,742
Income Before Interest Expense and Taxes									15,655	37,220	31,555
Assets	27,076				34,179				27,076	34,179	37,660
Payments to Acquire Property, Plant, and Equipment									273	2,681	1,366
Depreciation and amortization									1,624	1,393	945
Operating Segment Corporate And Other [Member]
Segment Reporting Information [Line Items]
Revenue, Net									0	0	0
Segment Reporting Information, Intersegment Revenue									(10,759)	(13,212)	(8,314)
Income Before Interest Expense and Taxes									(644)	483	811
Assets	$ 61,786				$ 62,686				61,786	62,686	44,834
Payments to Acquire Property, Plant, and Equipment									1,383	4,544	4,325
Depreciation and amortization									$ 2,444	$ 1,978	$ 1,883