Details of Selected Balance Sheet Accounts (Tables)

12 Months Ended

Dec. 31, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of accounts receivable

A summary of accounts receivable follows (in thousands):	December 31,
	2015			2014
Accounts receivable, principally trade	$	49,284		$	121,957
Less allowance for doubtful accounts	(4,919		)	(7,632		)
Accounts receivable, net	$	44,365		$	114,325

Summary of inventories

A summary of inventories follows (in thousands):	December 31,
	2015			2014
Raw materials and purchased subassemblies	$	34,949		$	41,461
Work-in-process	8,478			18,221
Finished goods	13,769			21,284
Reserve for excess and obsolete inventories	(24,475		)	(29,804		)
Total	$	32,721		$	51,162

Summary of Property, Plant, Equipment and Seismic Rental Equipment

Property, plant, equipment and seismic rental equipment are stated at cost. Depreciation expense is provided straight-line over the following estimated useful lives:

	Years
Machinery and equipment	3-7
Buildings	5-25
Seismic rental equipment	3-5
Leased equipment and other	3-10

A summary of property, plant, equipment and seismic rental equipment follows (in thousands):

	December 31,
	2015			2014
Buildings	$	24,181		$	25,343
Machinery and equipment	152,358			144,864
Seismic rental equipment	1,904			2,166
Furniture and fixtures	4,334			4,064
Other	31,821			16,481
Total	214,598			192,918
Less accumulated depreciation	(142,571		)	(123,078		)
Property, plant, equipment and seismic rental equipment, net	$	72,027		$	69,840

Summary of finite intangible assets, net

A summary of intangible assets, net, follows (in thousands):	December 31, 2015
	Gross Amount		Accumulated Amortization			Net
Customer relationships	$	37,469	$	(32,659	)	$	4,810
Total	$	37,469	$	(32,659	)	$	4,810

	December 31, 2014
	Gross Amount		Accumulated Amortization			Net
Customer relationships	$	40,234	$	(33,446	)	$	6,788
Intellectual property rights	3,350		(3,350		)	—
Total	$	43,584	$	(36,796	)	$	6,788

Estimated future amortization expense

A summary of the estimated amortization expense for the next five years follows (in thousands):

Years Ended December 31,
2016	$	1,675
2017	$	1,452
2018	$	1,225
2019	$	458

Summary of accrued expenses

A summary of other long-term liabilities follows (in thousands):	December 31,
	2015		2014
Accrual for loss contingency related to legal proceedings (Footnote 7)	$	22,000	$	123,770
Deferred lease liabilities	13,394		13,416
Facility restructuring accrual	3,006		4,667
Deferred income tax liability	4,734		—
Other	1,231		1,951
Total	$	44,365	$	143,804

A summary of accrued expenses follows (in thousands):	December 31,
	2015		2014
Compensation, including compensation-related taxes and commissions	$	19,126	$	33,386
Accrued multi-client data library acquisition costs	1,600		6,458
Deferred income tax liability	—		5,900
Income tax payable	—		8,865
Other	13,561		10,655
Total	$	34,287	$	65,264