Equity Method Investments Changes in Equity Method Investments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Schedule of Equity Method Investments [Line Items]
Investment balance, beginning balance	$ 53,865
Equity in earnings (losses) of investments	(1,688)	1,116
Advances to OceanGeo (prior to consolidation)	3,683
Acquisition of controlling interest (consolidation) of OceanGeo	(7,221)
Equity interest in investees' other comprehensive loss	(1,173)
Investment balance, ending balance	47,466
INOVA Geophysical [Member]
Schedule of Equity Method Investments [Line Items]
Investment balance, beginning balance	51,065
Equity in earnings (losses) of investments	(2,426)	1,900
Advances to OceanGeo (prior to consolidation)	0
Acquisition of controlling interest (consolidation) of OceanGeo	0
Equity interest in investees' other comprehensive loss	(1,173)
Investment balance, ending balance	47,466
OceanGeo [Member]
Schedule of Equity Method Investments [Line Items]
Investment balance, beginning balance	2,800
Equity in earnings (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