Industry Segments (Tables) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Product sales
Fluids Division	$ 68,430	$ 62,599	$ 127,934	$ 113,854
Offshore Services	1,192	499	2,127	1,147
Maritech	33,155	49,576	76,749	95,794
Total Offshore Division	34,347	50,075	78,876	96,941
Production Testing	0	0	0	3,610
Compressco	2,513	1,241	5,003	2,703
Total Production Enhancement Division	2,513	1,241	5,003	6,313
Consolidated product sales	105,290	113,915	211,813	217,108
Services and rentals
Fluids Division	20,365	16,714	38,191	31,704
Offshore Services	86,060	84,839	136,840	135,448
Maritech	227	759	655	1,140
Intersegment eliminations	(28,421)	(18,156)	(34,037)	(23,296)
Total Offshore Division	57,866	67,442	103,458	113,292
Production Testing	31,738	24,342	64,948	46,934
Compressco	19,813	19,205	39,207	38,473
Total Production Enhancement Division	51,551	43,547	104,155	85,407
Corporate overhead	42	0	42	0
Consolidated services and rentals	129,824	127,703	245,846	230,403
Intersegment revenues
Fluids Division	34	16	48	32
Offshore Services	3	63	3	204
Maritech	0	0	0	35
Total Offshore Division	3	63	3	239
Production Testing	1	4	1	4
Total Production Enhancement Division	1	4	1	4
Intersegment eliminations	(38)	(83)	(52)	(275)
Consolidated intersegment revenues	0	0	0	0
Total revenues
Fluids Division	88,829	79,329	166,173	145,590
Offshore Services	87,255	85,401	138,970	136,799
Maritech	33,382	50,335	77,404	96,969
Intersegment eliminations	(28,421)	(18,156)	(34,037)	(23,296)
Total Offshore Division	92,216	117,580	182,337	210,472
Production Testing	31,739	24,346	64,949	50,548
Compressco	22,326	20,446	44,210	41,176
Total Production Enhancement Division	54,065	44,792	109,159	91,724
Corporate overhead	42	0	42	0
Intersegment eliminations	(38)	(83)	(52)	(275)
Consolidated total revenues	235,114	241,618	457,659	447,511
Income before taxes and discontinued operations
Fluids Division	11,545	10,191	18,794	16,377
Offshore Services	13,577	14,269	9,201	11,828
Maritech	38,523	1,044	34,003	9,687
Intersegment eliminations	1,588	81	1,747	572
Total Offshore Division	53,688	15,394	44,951	22,087
Production Testing	5,988	3,020	15,071	7,015
Compressco	3,809	5,037	7,814	10,133
Total Production Enhancement Division	9,797	8,057	22,885	17,148
Corporate overhead	(27,476)	(13,104)	(43,117)	(26,602)
Consolidated income before taxes and discontinued operations	47,554	20,538	43,513	29,010
Total assets
Fluids Division	384,744	381,485	384,744	381,485
Offshore Services	167,749	177,656	167,749	177,656
Maritech	30,775	308,292	30,775	308,292
Intersegment eliminations	(55)	(1,674)	(55)	(1,674)
Total Offshore Division	198,469	484,274	198,469	484,274
Production Testing	97,675	101,997	97,675	101,997
Compressco	218,020	197,487	218,020	197,487
Total Production Enhancement Division	315,695	299,484	315,695	299,484
Corporate overhead	352,044	171,779	352,044	171,779
Consolidated total assets	$ 1,250,952	$ 1,337,022	$ 1,250,952	$ 1,337,022	$ 1,299,628