Equity Method Investments Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	4 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2013 GeoRXT [Member]	Jun. 30, 2013 GeoRXT [Member]	Mar. 31, 2013 INOVA Geophysical [Member]	Mar. 31, 2012 INOVA Geophysical [Member]	Mar. 31, 2013 INOVA Geophysical [Member]	Mar. 31, 2012 INOVA Geophysical [Member]
Schedule of Equity Method Investments [Line Items]
Net revenues	$ 13,698	$ 19,668	$ 22,095	$ 56,779	$ 81,706	$ 115,777
Gross profit	(195)	122	1,808	19,502	14,135	33,466
Income (loss) from operations	(5,107)	(6,876)	(8,511)	8,910	(8,761)	15,419
Net income	$ (5,151)	$ (7,045)	$ (9,772)	$ 8,654	$ (6,030)	$ 14,371