Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 40,225	$ 52,652	$ 62,536	$ 84,933
Accounts receivable, net	39,374	20,770
Unbilled receivables	25,833	13,415
Inventories	14,264	15,241
Prepaid expenses and other current assets	4,259	9,559
Total current assets	123,955	111,637
Property, plant, equipment and seismic rental equipment, net	55,188	67,488
Multi-client data library, net	96,751	105,935
Goodwill	24,048	22,208
Intangible assets, net	2,026	3,103
Other assets	1,485	2,845
Total assets	303,453	313,216
Current liabilities:
Current maturities of long-term debt	38,819	14,581
Accounts payable	24,674	26,889
Accrued expenses	40,874	26,240
Accrued multi-client data library royalties	24,576	23,663
Deferred revenue	10,875	3,709
Total current liabilities	139,818	95,082
Long-term debt, net of current maturities	116,506	144,209
Other long-term liabilities	17,066	20,527
Total liabilities	273,390	259,818
Equity:
Common stock, $0.01 par value; authorized 26,666,667 shares; outstanding 11,896,190 and 11,792,447 shares at September 30, 2017 and December 31, 2016, respectively	119	118
Additional paid-in capital	901,138	899,198
Accumulated deficit	(853,527)	(824,679)
Accumulated other comprehensive loss	(18,999)	(21,748)
Total stockholders’ equity	28,731	52,889
Noncontrolling interest	1,332	509
Total equity	30,063	53,398
Total liabilities and equity	$ 303,453	$ 313,216