Asset Retirement Obligations Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2019

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Change in Asset Retirement Obligation [Table Text Block]

The following table presents the changes in carrying amounts of the asset retirement obligations associated with our working interest in crude oil and natural gas properties:

	Year Ended December 31,
	2019			2018
	(in thousands)
Beginning balance	$	115,021		$	87,306
Obligations incurred with development activities	4,605			2,793
Obligations incurred with acquisition	2,882			4,332
Accretion expense	6,117			5,075
Revisions in estimated cash flows	28,991			30,166
Obligations discharged with asset retirements	(23,426		)	(14,651		)
Obligations discharged with divestitures	(6,939		)	—
Balance at December 31	127,251			115,021
Liabilities held-for-sale	—			(4,111		)
Current portion	(32,200		)	(25,598		)
Long-term portion	$	95,051		$	85,312