Equity Method Investments Changes in Equity Method Investments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Equity Method Investments [Roll Forward]
Investment balance, beginning balance			$ 53,865
Equity in losses of investments	(1,781)	(6,338)	(3,469)	(5,222)
Advances to OceanGeo (prior to consolidation)			3,683
Acquisition of controlling interest (consolidation) of OceanGeo			(7,221)
Equity interest in investees' other comprehensive loss			(1,863)
Investment balance, ending balance	44,995		44,995
INOVA Geophysical [Member]
Equity Method Investments [Roll Forward]
Investment balance, beginning balance			51,065
Equity in losses of investments	(1,800)	(4,700)	(4,207)	(2,900)
Advances to OceanGeo (prior to consolidation)			0
Acquisition of controlling interest (consolidation) of OceanGeo			0
Equity interest in investees' other comprehensive loss			(1,863)
Investment balance, ending balance	44,995		44,995
OceanGeo [Member]
Equity Method Investments [Roll Forward]
Investment balance, beginning balance			2,800
Equity in losses of investments			738
Advances to OceanGeo (prior to consolidation)			3,683
Acquisition of controlling interest (consolidation) of OceanGeo			(7,221)
Equity interest in investees' other comprehensive loss			0
Investment balance, ending balance	$ 0		$ 0