Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment [Table Text Block]

As of December 31, 2017 and 2016, the estimated useful lives and costs of our asset classes are as follows:

		As of December 31,
		2017		2016
	Lives	Cost (amounts in thousands)
Drilling rigs and equipment	3 - 25	$	594,743	$	582,477
Well servicing rigs and equipment	3 - 20	244,747		225,125
Wireline units and equipment	1 - 10	142,224		141,959
Coiled tubing units and equipment	1 - 7	18,141		16,347
Vehicles	3 - 10	47,932		45,424
Office equipment	3 - 10	12,717		11,628
Buildings and improvements	3 - 40	24,013		23,884
Property and equipment not yet placed in service	—	6,751		9,050
Land	—	2,367		2,367
		$	1,093,635	$	1,058,261

Schedule of Impairment Charges [Table Text Block]

The following table summarizes impairment expense recognized during the years ended December 31, 2017, 2016, and 2015(amounts in thousands):

	Year ended December 31,
	2017		2016		2015
Assets held for sale	$	1,902	$	11,897	$	9,858
Colombian assets	—		—		60,130
Domestic drilling rigs and equipment	—		918		28,228
Coiled tubing assets	—		—		30,936
	$	1,902	$	12,815	$	129,152