Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 144,438	$ 173,608	$ 197,306	$ 148,056
Accounts receivable, net	39,369	114,325
Unbilled receivables	24,098	22,599
Inventories	42,976	51,162
Prepaid expenses and other current assets	13,007	13,662
Total current assets	263,888	375,356
Deferred income tax asset	8,605	8,604
Property, plant, equipment and seismic rental equipment, net	79,739	69,840
Multi-client data library, net	128,598	118,669
Goodwill	26,289	27,388
Intangible assets, net	6,276	6,788
Other assets	10,064	10,612
Total assets	523,459	617,257
Current liabilities:
Current maturities of long-term debt	7,242	7,649
Accounts payable	29,150	36,863
Accrued expenses	50,849	65,264
Accrued multi-client data library royalties	15,604	35,219
Deferred revenue	11,327	8,262
Total current liabilities	114,172	153,257
Long-term debt, net of current maturities	182,421	182,945
Other long-term liabilities	144,979	143,804
Total liabilities	441,572	480,006
Redeemable noncontrolling interest	1,325	1,539
Equity:
Common stock, $0.01 par value; authorized 200,000,000 shares; outstanding 164,686,976 and 164,484,095 shares at March 31, 2015 and December 31, 2014, respectively, net of treasury stock	1,647	1,645
Additional paid-in capital	889,255	887,749
Accumulated deficit	(789,673)	(734,409)
Accumulated other comprehensive loss	(14,152)	(12,807)
Treasury stock, at cost, 849,539 shares at both March 31, 2015 and December 31, 2014	(6,565)	(6,565)
Total stockholders' equity	80,512	135,613
Noncontrolling interest	50	99
Total equity	80,562	135,712
Total liabilities and equity	$ 523,459	$ 617,257