CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 29,563		$ 33,551	$ 44,349
Accounts receivable, net	17,603		26,128
Unbilled receivables	22,524		44,032
Inventories, net	13,393		14,130
Prepaid expenses and other current assets	7,754		7,782
Total current assets	90,837		125,623
Deferred income tax asset, net	7,659		7,191
Property, plant and equipment, net	13,114		13,041
Multi-client data library, net	66,461		73,544
Goodwill	22,907		22,915
Right-of-use assets	39,926		47,803
Other assets	1,517		2,435
Total assets	242,421		292,552
Current liabilities:
Current maturities of long-term debt	1,376		2,228
Accounts payable	36,399		34,913
Accrued expenses	32,243		31,411
Accrued multi-client data library royalties	16,469		29,256
Deferred revenue	4,386		7,710
Current maturities of operating lease liabilities	11,820		12,214
Total current liabilities	102,693		117,732
Long-term debt, net of current maturities	119,445		119,513
Operating lease liabilities, net of current maturities	38,063		45,592
Other long-term liabilities	1,601		1,891
Total liabilities	261,802		284,728
(Deficit) Equity:
Common stock, $0.01 par value; authorized 26,666,667 shares; outstanding 14,171,561 and 14,015,615 shares at June 30, 2019 and December 31, 2018, respectively.	142		140
Additional paid-in capital	954,904		952,626
Accumulated deficit	(956,074)		(926,092)
Accumulated other comprehensive loss	(20,412)		(20,442)
Total stockholders’ (deficit) equity	(21,440)		6,232
Noncontrolling interest	2,059		1,592
Total (deficit) equity	(19,381)	$ (11,439)	7,824	$ 33,921	$ 61,519	$ 30,806
Total liabilities and (deficit) equity	$ 242,421		$ 292,552