CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (18,339)	$ (23,026)
Adjustments to reconcile net loss to cash provided by operating activities:
Depreciation and amortization (other than multi-client data library)	2,523	4,677
Amortization of multi-client data library	9,793	9,258
Stock-based compensation expense	812	634
Accrual for loss contingency related to legal proceedings	0	5,000
Deferred income taxes	(117)	(1,909)
Change in operating assets and liabilities:
Accounts receivable	(10,084)	4,756
Unbilled receivables	20,919	(5,348)
Inventories	(164)	(274)
Accounts payable, accrued expenses and accrued royalties	(10,155)	(2,488)
Deferred revenue	2,381	7,193
Other assets and liabilities	3,039	3,368
Net cash provided by operating activities	608	1,841
Cash flows from investing activities:
Cash invested in multi-client data library	(9,240)	(3,363)
Purchase of property, plant, equipment and seismic rental assets	(61)	(49)
Net cash used in investing activities	(9,301)	(3,412)
Cash flows from financing activities:
Payments under revolving line of credit	(10,000)	0
Payments on notes payable and long-term debt	(29,144)	(1,706)
Net proceeds from issuance of stock	47,219	0
Other financing activities	(575)	(286)
Net cash provided by (used in) financing activities	7,500	(1,992)
Effect of change in foreign currency exchange rates on cash, cash equivalents and restricted cash	(113)	409
Net decrease in cash, cash equivalents and restricted cash	(1,306)	(3,154)
Cash, cash equivalents and restricted cash at beginning of period	52,419	53,433
Cash, cash equivalents and restricted cash at end of period	$ 51,113	$ 50,279