Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property Plant And Equipment [Abstract]

Property and Equipment

Property and equipment consisted of the following at December 31, 2016 and 2015 (in thousands):

	2016			2015
Equipment	$	6,809,129		$	6,963,148
Oil and natural gas properties		201,568			200,923
Buildings		97,029			96,470
Land		22,270			22,370
Total property and equipment		7,129,996			7,282,911
Less accumulated depreciation, depletion and impairment		(3,721,033	)		(3,362,203	)
Property and equipment, net	$	3,408,963		$	3,920,708

Summary of Depreciation, Depletion, Amortization and Impairment Expense related to Property and Equipment and Intangible Assets

Depreciation, depletion, amortization and impairment — The following table summarizes depreciation, depletion, amortization and impairment expense related to property and equipment and intangible assets for 2016, 2015 and 2014 (in thousands):

	2016		2015		2014
Depreciation and impairment expense	$	657,571	$	845,543	$	693,390
Amortization expense		3,643		3,643		3,643
Depletion expense		7,220		15,573		21,697
Total	$	668,434	$	864,759	$	718,730