Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2020

Asset Retirement Obligation Disclosure [Abstract]

Activity Related to Asset Retirement Obligations

Activity related to the Company's asset retirement obligations is as follows:

	Year Ended December 31,
(In thousands)	2020		2019
Balance at beginning of period	$	72,098	$	51,622
Liabilities incurred	10,008		7,646
Liabilities settled	(322)		(1,467)
Accretion expense	4,205		3,430
Change in estimate	—		10,867
Balance at end of period	85,989		72,098
Less: current asset retirement obligation	(500)		(500)
Noncurrent asset retirement obligation	$	85,489	$	71,598