Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

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,
	2017			2016
Buildings	$	15,822		$	17,424
Machinery and equipment	145,654			157,618
Seismic rental equipment	1,677			1,557
Furniture and fixtures	3,869			3,905
Other	28,965			30,049
Total	195,987			210,553
Less accumulated depreciation	(143,834		)	(143,065		)
Property, plant, equipment and seismic rental equipment, net	$	52,153		$	67,488

Schedule of Multi-Client Data Library

At December 31, 2017 and 2016, multi-client data library costs and accumulated amortization consisted of the following (in thousands):

	December 31,
	2017			2016
Gross costs of multi-client data creation	$	939,077		$	906,306
Less accumulated amortization	(727,872		)	(680,770		)
Less impairments to multi-client data library	(121,905		)	(119,601		)
Total	$	89,300		$	105,935