Equity Method Investments Changes in Equity Method Investments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Equity Method Investments [Line Items]
Investment balance, beginning balance			$ 73,925
Investment in equity			1,500
Notes receivable			8,000
Equity in earnings (losses) of investments	(5,192)	(1,684)	(10,414)	4,561
Write-down of note receivable from OceanGeo			(2,122)
Equity interest in investees' other comprehensive income (loss)			(1,265)
Investment balance, ending balance	69,624		69,624
INOVA Geophysical [Member]
Schedule of Equity Method Investments [Line Items]
Investment balance, beginning balance			73,925
Investment in equity			0
Notes receivable			0
Equity in earnings (losses) of investments	(200)	(1,684)	(3,036)	4,561
Write-down of note receivable from OceanGeo			0
Equity interest in investees' other comprehensive income (loss)			(1,265)
Investment balance, ending balance	69,624		69,624
OceanGeo [Member]
Schedule of Equity Method Investments [Line Items]
Investment balance, beginning balance			0
Investment in equity			1,500
Notes receivable			8,000
Equity in earnings (losses) of investments	(5,000)		(7,378)
Write-down of note receivable from OceanGeo			(2,122)
Equity interest in investees' other comprehensive income (loss)			0
Investment balance, ending balance	$ 0		$ 0