CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 27,894		$ 33,551	$ 30,043
Accounts receivable, net	23,832		26,128
Unbilled receivables	30,990		44,032
Inventories, net	12,934		14,130
Prepaid expenses and other current assets	6,626		7,782
Total current assets	102,276		125,623
Deferred income tax asset, net	8,435		7,191
Property, plant and equipment, net	12,903		13,041
Multi-client data library, net	69,723		73,544
Goodwill	22,276		22,915
Right-of-use assets	37,155		47,803
Other assets	2,222		2,435
Total assets	254,990		292,552
Current liabilities:
Current maturities of long-term debt	1,110		2,228
Accounts payable	43,565		34,913
Accrued expenses	42,807		31,411
Accrued multi-client data library royalties	17,514		29,256
Deferred revenue	5,310		7,710
Current maturities of operating lease liabilities	11,648		12,214
Total current liabilities	121,954		117,732
Long-term debt, net of current maturities	119,402		119,513
Operating lease liabilities, net of current maturities	35,214		45,592
Other long-term liabilities	1,526		1,891
Total liabilities	278,096		284,728
(Deficit) Equity:
Common stock, $0.01 par value; authorized 26,666,667 shares; outstanding 14,201,650 and 14,015,615 shares at September 30, 2019 and December 31, 2018, respectively.	142		140
Additional paid-in capital	955,705		952,626
Accumulated deficit	(959,797)		(926,092)
Accumulated other comprehensive loss	(21,440)		(20,442)
Total stockholders’ (deficit) equity	(25,390)		6,232
Noncontrolling interest	2,284		1,592
Total (deficit) equity	(23,106)	$ (19,381)	7,824	$ 26,914	$ 33,921	$ 30,806
Total liabilities and (deficit) equity	$ 254,990		$ 292,552