Segment Information (Details 1) (INOVA Geophysical [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
INOVA Geophysical [Member]
Summarized financial information of net income loss by segment
Net revenues	$ 56,779	$ 32,452	$ 115,777	$ 77,991
Gross profit	19,502	3,708	33,466	14,924
Income (loss) from operations	8,910	(6,657)	15,419	(9,867)
Net income (loss)	$ 8,654	$ (8,090)	$ 14,371	$ (10,771)