Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property Plant And Equipment [Abstract]

Property and equipment consisted of the following at December 31, 2020 and 2019 (in thousands):

	2020			2019
Equipment	$	7,647,451		$	8,114,326
Oil and natural gas properties		222,738			226,646
Buildings		193,503			184,700
Land		25,781			25,747
Total property and equipment		8,089,473			8,551,419
Less accumulated depreciation, depletion, amortization and impairment		(5,328,432	)		(5,244,742	)
Property and equipment, net	$	2,761,041		$	3,306,677

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

Depreciation, depletion, amortization and impairment — The following table summarizes depreciation, depletion, amortization and impairment expense related to property and equipment, intangible assets and liabilities for 2020, 2019 and 2018 (in thousands):

	2020		2019		2018
Depreciation and impairment expense	$	644,943	$	974,206	$	887,155
Amortization expense		19,281		17,722		18,197
Depletion expense		6,686		11,945		10,966
Total	$	670,910	$	1,003,873	$	916,318