Supplemental Cash Flow Information and Non-cash Activity

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Supplemental Cash Flow Information and Non-cash Activity

Supplemental Cash Flow Information and Non-Cash Activity

Supplemental disclosure of cash flow information follows (in thousands):

	Years Ended December 31,
	2017		2016			2015
Cash paid during the period for:
Interest	$	14,181	$	15,691		$	15,441
Income taxes	7,030		4,474			8,163
Non-cash items from investing and financing activities:
Purchase of computer equipment financed through capital leases	—		—			1,178
Leasehold improvement paid by landlord	—		955			—
Issuance of stock in bond exchange	—		10,741			—
Transfer of inventory to property, plant and equipment	—		17,662		(a)	15,936		(b)
Investment in multi-client data library financed through trade payables	9,059		—			8,939

^(a)  This transfer of $17.7 million of inventory to property, plant, equipment and seismic rental equipment in December 2016, relates to ocean bottom seismic equipment manufactured by the Company to be deployed in the acquisition of ocean bottom seismic data.

^(b)  This transfer of inventory to property, plant, equipment and seismic rental equipment relates to ocean bottom seismic equipment manufactured by the Company to be deployed in the acquisition of ocean bottom seismic data. During the twelve months ended December 31, 2015, the Company purchased approximately $19.2 million of property, plant, equipment and seismic rental equipment, including approximately $15.3 million related to the manufacture of ocean bottom seismic equipment that will be used by the Ocean Bottom Seismic Services segment.