Equity Method Investment in INOVA Geophysical (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
Equity Method Investment Summarized Financial Information Income Statements
Total net revenues	$ 188,336	$ 138,735		$ 47,609
Gross profit (loss)	39,320	5,765	[1]	(21,574)	[2]
Loss from operations	3,241	(41,836)		(45,423)
Net loss	$ 2,197	$ (46,033)		$ (48,416)

[1] Includes approximately $15.7 million of excess inventory charge reflected in INOVA’s third quarter of 2011 and ION’s fourth quarter of 2011.

[2] Includes approximately $19.3 million of excess inventory charge reflected in INOVA’s third quarter of 2010 and ION’s fourth quarter of 2010.