Equity Method Investments Narrative (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended				3 Months Ended		9 Months Ended							3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013 OceanGeo [Member]	Sep. 30, 2013 OceanGeo [Member]	Jun. 30, 2013 OceanGeo [Member]	Feb. 19, 2013 OceanGeo [Member]	Dec. 31, 2012 OceanGeo [Member]	Sep. 30, 2013 INOVA Geophysical [Member]	Sep. 30, 2012 INOVA Geophysical [Member]	Sep. 30, 2013 INOVA Geophysical [Member]	Sep. 30, 2012 INOVA Geophysical [Member]	Dec. 31, 2012 INOVA Geophysical [Member]	Sep. 30, 2013 Optional Increase in Ownership [Member] OceanGeo [Member]	Nov. 15, 2013 Subsequent Event OceanGeo [Member]	Oct. 31, 2013 Subsequent Event Optional Increase in Ownership [Member] OceanGeo [Member]	Sep. 30, 2013 Notes Receivable [Member] OceanGeo [Member]	Sep. 30, 2013 INOVA Geophysical [Member] position
Schedule of Equity Method Investments [Line Items]
Investment in equity									$ 1,500,000
Percentage of equity method investment									30.00%		49.00%		49.00%			50.00%		70.00%
Working capital loan to investee									8,000,000								7,900,000
Equity in earnings (losses) of investments	(5,192,000)	(1,684,000)	(10,414,000)	4,561,000		(5,000,000)	(7,378,000)				(200,000)	(1,684,000)	(3,036,000)	4,561,000
Equity method investments	69,624,000		69,624,000		73,925,000	0	0			0	69,624,000		69,624,000		73,925,000
Value of receivables due from related party								0											(2,100,000)
Value of remaining receivables due from related party								(9,200,000)
Write-down of note receivable from OceanGeo			$ (9,157,000)	$ 0
Number of positions eliminated																				77
Number of positions eliminated, percent																				20.00%