Property and Equipment

3 Months Ended

Mar. 31, 2018

Property, Plant and Equipment [Abstract]

The historical costs of our property and equipment and related accumulated depreciation balances were as follows at the dates indicated (in thousands):



	Estimated
	Useful Life	March 31,			December 31,
	in Years	2018			2017

Tractors and trailers ⁽¹⁾	5 – 6	$	86,492		$	88,065
Field equipment	2 – 5	18,827			18,490
Buildings	5 – 39	15,728			15,727
Office equipment	1 – 5	1,831			1,929
Land		1,790			1,790
Construction in progress		761			275
Total		125,429			126,276
Less accumulated depreciation		(97,685		)	(96,914		)
Property and equipment, net		$	27,744		$	29,362

______________

(1)

Amounts include assets held under capital leases for certain tractors in our marketing segment. Gross property and equipment associated with assets held under capital leases were $1.8 million and $1.8 million at March 31, 2018 and December 31, 2017, respectively. Accumulated amortization associated with assets held under capital leases were $0.2 million and $0.1 million at March 31, 2018 and December 31, 2017, respectively (see Note 11 for further information).

Components of depreciation, depletion and amortization expense were as follows for the periods indicated (in thousands):



	Three Months Ended
	March 31,
	2018		2017
Depreciation, depletion and amortization, excluding amounts
under capital leases	$	2,322	$	3,969
Amortization of property and equipment under capital leases	90		—
Total depreciation, depletion and amortization	$	2,412	$	3,969