Acquisition of OceanGeo - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended				3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jul. 31, 2014 OceanGeo [Member]	Sep. 30, 2014 OceanGeo [Member]	Sep. 30, 2014 OceanGeo [Member]	Jan. 31, 2014 OceanGeo [Member]	Oct. 31, 2013 OceanGeo [Member]	Feb. 28, 2013 OceanGeo [Member]	Sep. 30, 2014 Property, Plant and Equipment [Member]
Business Acquisition [Line Items]
Increase in ownership percentage					30.00%			40.00%		30.00%
Ownership percentage interest					100.00%			70.00%
Loan made to equity method investee									$ 25,000,000.0
Working capital loan to investee						46,500,000	46,500,000		18,900,000
Total consideration					6,000,000
Contingent payment to acquiree					5,000,000
Retrospective adjustments from adjusted purchase accounting valuation estimates											3,900,000
Acquisition related costs							1,300,000
Income (loss) from operations	(5,349,000)	(56,528,000)	18,107,000	(47,835,000)		1,700,000	12,300,000
Revenues	$ 106,540,000	$ 79,838,000	$ 372,718,000	$ 330,490,000		$ 25,000,000	$ 71,500,000