Segment Reporting Level 4 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 655,443	$ 610,678	$ 636,516
Capital expenditures	8,443	7,297
Depreciation and amortization	6,025	5,883
Total Revenue	260,927	234,191
Segment Reporting Information, Intersegment Revenue	0	0
OPERATING INCOME	79,037	73,906
Operating Segment Reservoir Description [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	300,483	271,320
Capital expenditures	5,429	2,479
Depreciation and amortization	3,625	3,547
Total Revenue	125,245	116,106
Segment Reporting Information, Intersegment Revenue	2,280	536
OPERATING INCOME	34,851	32,415
Operating Segment Production Enhancement [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	255,947	248,866
Capital expenditures	2,088	1,842
Depreciation and amortization	1,817	1,598
Total Revenue	107,431	96,733
Segment Reporting Information, Intersegment Revenue	2,757	468
OPERATING INCOME	34,238	33,531
Operating Segment Reservoir Management [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	38,605	24,191
Capital expenditures	519	411
Depreciation and amortization	191	167
Total Revenue	28,251	21,352
Segment Reporting Information, Intersegment Revenue	1,492	19
OPERATING INCOME	9,846	7,915
Operating Segment Corporate And Other [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	60,408	66,301
Capital expenditures	407	2,565
Depreciation and amortization	392	571
Total Revenue	0	0
Segment Reporting Information, Intersegment Revenue	(6,529)	(1,023)
OPERATING INCOME	$ 102	$ 45