Consolidated Statements Of Operations (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net revenues
Rentals	$ 46,795	$ 43,384	$ 38,606
Product sales	7,842	3,845	358
Net revenues	54,637	47,229	38,964
Cost of revenues:
Cost of revenues - Product, service and supply costs	9,128	7,730	6,200
Cost of revenues - Pump depreciation, sales and disposals	10,154	5,954	4,127
Gross profit	35,355	33,545	28,637
Selling, general and administrative expenses:
Provision for doubtful accounts	4,099	4,515	4,006
Amortization of intangibles	2,662	2,259	1,827
Asset impairment charges	67,592
Selling and marketing	9,371	7,087	5,258
General and administrative	17,987	20,622	12,218
Total sales, general and administrative:	101,711	34,483	23,309
Operating (loss) income	(66,356)	(938)	5,328
Other income (loss):
Gain (loss) on derivatives	83	207	(78)
Interest expense	(2,193)	(3,352)	(3,499)
Gain on extinguishment of long term debt		1,118
Other expense	(111)	(258)
Total other loss	(2,221)	(2,285)	(3,577)
(Loss) income before income taxes	(68,577)	(3,223)	1,751
Income tax benefit (expense)	23,134	1,371	(977)
Net (loss) income	$ (45,443)	$ (1,852)	$ 774
Net (loss) income per share:
Basic	$ (2.16)	$ (0.09)	$ 0.04
Diluted	$ (2.16)	$ (0.09)	$ 0.04
Weighted average shares outstanding:
Basic	21,074,093	19,721,378	18,609,797
Diluted	21,074,093	19,721,378	18,931,356