Revenue Recognition (Revenue from Non-Monetary Exchanges) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Nonmonetary Transaction [Line Items]
Seismic data library additions	$ 2,716	$ 709
Revenue recognized	635	2,115
Specific Data Licenses or Selections of Data [Member]
Nonmonetary Transaction [Line Items]
Revenue recognized	578	827
Acquisition Contracts [Member]
Nonmonetary Transaction [Line Items]
Revenue recognized	57	1,268
Solutions [Member]
Nonmonetary Transaction [Line Items]
Revenue recognized	0	20
Seismic Data Library [Member]
Nonmonetary Transaction [Line Items]
Seismic data library additions	$ 2,716	$ 709