Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (23,026)	$ (35,036)
Adjustments to reconcile net loss to cash provided by operating activities:
Depreciation and amortization (other than multi-client data library)	4,677	5,672
Amortization of multi-client data library	9,258	7,139
Stock-based compensation expense	634	743
Accrual for loss contingency related to legal proceedings	5,000	0
Deferred income taxes	(1,909)	54
Change in operating assets and liabilities:
Accounts receivable	4,756	29,211
Unbilled receivables	(5,348)	2,212
Inventories	(274)	350
Accounts payable, accrued expenses and accrued royalties	(2,488)	(10,558)
Deferred revenue	7,193	(527)
Other assets and liabilities	3,510	3,219
Net cash provided by operating activities	1,983	2,479
Cash flows from investing activities:
Cash invested in multi-client data library	(3,363)	(6,327)
Purchase of property, plant, equipment and seismic rental assets	(49)	(266)
Net cash used in investing activities	(3,412)	(6,593)
Cash flows from financing activities:
Repurchase of common stock	0	(964)
Payments on notes payable and long-term debt	(1,706)	(2,212)
Costs associated with issuance of debt	0	(1,315)
Costs associated with issuance of equity	(123)
Other financing activities	(163)	13
Net cash used in financing activities	(1,992)	(4,478)
Effect of change in foreign currency exchange rates on cash and cash equivalents	409	329
Net decrease in cash, and cash equivalents	(3,012)	(8,263)
Cash and cash equivalents at beginning of period	52,652	84,933
Cash and cash equivalents at end of period	$ 49,640	$ 76,670