Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (19,900)	$ 54,010
Adjustments to reconcile net income (loss) to cash (used in) provided by operating activities:
Depreciation and amortization (other than multi-client data library)	19,660	20,989
Amortization of multi-client data library	24,531	46,014
Stock-based compensation expense	4,174	7,058
Reductions of accrual for loss contingency related to legal proceedings	(101,978)	(69,557)
Equity in losses of investments	0	9,027
Gain on sale of Source product line	0	(6,522)
Deferred income taxes	5,992	(1,536)
Change in operating assets and liabilities:
Accounts receivable	92,424	71,540
Unbilled receivables	(9,837)	(8,036)
Inventories	464	(4,272)
Accounts payable, accrued expenses and accrued royalties	(43,676)	(31,324)
Deferred revenue	(2,576)	(4,153)
Other assets and liabilities	(5,274)	3,738
Net cash (used in) provided by operating activities	(35,996)	86,976
Cash flows from investing activities:
Cash invested in multi-client data library	(28,152)	(57,340)
Purchase of property, plant, equipment and seismic rental assets	(17,601)	(6,842)
Repayment of advance to INOVA Geophysical	0	1,000
Net investment in and advances to OceanGeo B.V. prior to its consolidation	0	(3,074)
Net proceeds from sale of Source product line	0	14,394
Other investing activities	1,262	928
Net cash used in investing activities	(44,491)	(50,934)
Cash flows from financing activities:
Borrowings under revolving line of credit	0	15,000
Payments under revolving line of credit	0	(50,000)
Payments on notes payable and long-term debt	(5,431)	(11,737)
Costs associated with issuance of debt	(146)	(2,126)
Acquisition of non-controlling interest	0	(6,000)
Other financing activities	94	423
Net cash used in financing activities	(5,483)	(54,440)
Effect of change in foreign currency exchange rates on cash and cash equivalents	601	189
Net decrease in cash and cash equivalents	(85,369)	(18,209)
Cash and cash equivalents at beginning of period	173,608	148,056
Cash and cash equivalents at end of period	$ 88,239	$ 129,847