Equity Method Investments Income (Loss) (Details) (INOVA Geophysical [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
INOVA Geophysical [Member]
Schedule of Equity Method Investments [Line Items]
Net revenues	$ 11,092	$ 61,241	$ 77,774	$ 142,947
Gross profit (loss)	(2,164)	12,243	8,020	26,378
Income (loss) from operations	(9,851)	1,658	(16,094)	(7,103)
Net loss	$ (11,425)	$ (488)	$ (20,010)	$ (6,518)