Statement Of Cash Flow Information (Non-Cash Additions and Non-Cash Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Nonmonetary Transaction
Non-monetary exchanges related to resale licensing revenue			$ 7,961	$ 177
Adjustment to prior year non-monetary exchange from underwriting of new data acquisition			(2)	0
Total non-cash additions to seismic data library			7,959	177
Non-cash revenue			6,805	260
Acquisition revenue on underwriting [Member]
Nonmonetary Transaction
Non-cash revenue	$ 2	$ 0	166	0
Licensing revenue from specific data licenses and selections [Member]
Nonmonetary Transaction
Non-cash revenue	913	22	6,626	260
Solutions revenue [Member]
Nonmonetary Transaction
Non-cash revenue	$ 13	$ 0	$ 13	$ 0