Decommissioning and Other Asset Retirement Obligations (Tables)

9 Months Ended

Sep. 30, 2017

Asset Retirement Obligation Disclosure [Abstract]

Decommissioning and Other Asset Retirement Obligations Table

	Three Months Ended September 30, 2017			Nine Months Ended September 30, 2017
	(In Thousands)
Beginning balance for the period, as reported	$	55,999		$	55,478
Activity in the period:
Accretion of liability	551			1,582
Retirement obligations incurred	—			—
Revisions in estimated cash flows	26			12
Settlement of retirement obligations	(59		)	(555		)
Ending balance	$	56,517		$	56,517