Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 8,462	$ 450
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization (other than multi-client library)	3,090	3,953
Amortization of multi-client library	22,620	23,443
Stock-based compensation expense	1,484	1,973
Equity in (earnings) losses of INOVA Geophysical	(2,468)	860
Deferred income taxes	(1,063)	(2,854)
Change in operating assets and liabilities:
Accounts receivable	61,018	14,508
Unbilled receivables	(23,016)	29,593
Inventories	965	(13,404)
Accounts payable, accrued expenses and accrued royalties	(13,025)	(21,862)
Deferred revenue	(4,736)	15,537
Other assets and liabilities	(1,491)	(371)
Net cash provided by operating activities	51,840	51,826
Cash flows from investing activities:
Investment in multi-client data library	(24,527)	(11,907)
Purchase of property, plant and equipment	(1,768)	(3,674)
Sales (purchases) of short-term investments	20,000	(80,000)
Net cash used in investing activities	(6,295)	(95,581)
Cash flows from financing activities:
Payments on long-term debt	(1,431)	(1,748)
Payment of preferred dividends	(338)	(338)
Contribution from noncontrolling interest	68	200
Proceeds from exercise of stock options	249	11,793
Other financing activities	385	(37)
Net cash (used in) provided by financing activities	(1,067)	9,870
Effect of change in foreign currency exchange rates on cash and cash equivalents	216	300
Net increase (decrease) in cash and cash equivalents	44,694	(33,585)
Cash and cash equivalents at beginning of period	42,402	84,419
Cash and cash equivalents at end of period	$ 87,096	$ 50,834