Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenue, Net	$ 276,279	$ 273,163	$ 263,139	$ 260,927	$ 254,455	$ 245,428	$ 247,006	$ 234,191	$ 1,073,508	$ 981,080	$ 907,648
Segment Reporting Information, Intersegment Revenue									0	0	0
Income Before Interest Expense and Taxes	87,917	84,596	81,869	79,037	75,868	75,380	72,126	73,906	333,419	297,280	250,754
Assets	661,010				636,516				661,010	636,516	610,873
Payments to Acquire Property, Plant, and Equipment									35,416	31,151	29,927
Depreciation and amortization									25,471	22,917	23,303
Operating Segment Reservoir Description [Member]
Segment Reporting Information [Line Items]
Revenue, Net									522,251	495,529	469,775
Segment Reporting Information, Intersegment Revenue									3,432	2,484	1,515
Income Before Interest Expense and Taxes									146,338	144,502	116,244
Assets	321,106				293,974				321,106	293,974	270,270
Payments to Acquire Property, Plant, and Equipment									22,601	16,987	15,320
Depreciation and amortization									14,898	14,094	14,073
Operating Segment Production Enhancement [Member]
Segment Reporting Information [Line Items]
Revenue, Net									452,415	403,792	371,449
Segment Reporting Information, Intersegment Revenue									3,140	2,757	1,947
Income Before Interest Expense and Taxes									154,715	128,602	112,576
Assets	255,764				242,254				255,764	242,254	221,599
Payments to Acquire Property, Plant, and Equipment									7,124	7,423	8,700
Depreciation and amortization									7,745	6,139	6,449
Operating Segment Reservoir Management [Member]
Segment Reporting Information [Line Items]
Revenue, Net									98,842	81,759	66,424
Segment Reporting Information, Intersegment Revenue									1,742	1,492	1,686
Income Before Interest Expense and Taxes									31,555	26,428	21,887
Assets	37,660				34,532				37,660	34,532	26,070
Payments to Acquire Property, Plant, and Equipment									1,366	920	1,318
Depreciation and amortization									945	731	666
Operating Segment Corporate And Other [Member]
Segment Reporting Information [Line Items]
Revenue, Net									0	0	0
Segment Reporting Information, Intersegment Revenue									(8,314)	(6,733)	(5,148)
Income Before Interest Expense and Taxes									811	(2,252)	47
Assets	46,480				65,756				46,480	65,756	92,934
Payments to Acquire Property, Plant, and Equipment									4,325	5,821	4,589
Depreciation and amortization									$ 1,883	$ 1,953	$ 2,115