Decommissioning Liability (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Accretion expense	$ 2.3	$ 2.7
Decommissioning liability	162.6		$ 160.7
Decommissioning costs	$ 0.4

Amount of accretion expense, which includes, but is not limited to, accretion expense from asset retirement obligations, environmental remediation obligations, and other contingencies.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

Name:	us-gaap_AccretionExpenseIncludingAssetRetirementObligations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration