Fair Value (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Level 1 [Member]
Total Assets	$ 0.4	$ 0.4
Level 1 [Member] \| Subsidiaries [Member]
Total Assets	0.4	0.4
Level 2 [Member]
Total Assets	6.8	9.0
Level 2 [Member] \| Subsidiaries [Member]
Total Assets	6.8	9.0
Level 3 [Member]
Total Assets	0.0	0.0
Level 3 [Member] \| Subsidiaries [Member]
Total Assets	0.0	0.0
Fair Value [Member]
Total Assets	7.2	9.4
Fair Value [Member] \| Subsidiaries [Member]
Total Assets	7.2	9.4
Money Market Funds [Member] \| Level 1 [Member]
Investments, Fair Value Disclosure	0.4	0.4
Money Market Funds [Member] \| Level 1 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.4	0.4
Money Market Funds [Member] \| Level 2 [Member]
Investments, Fair Value Disclosure	0.0	0.0
Money Market Funds [Member] \| Level 2 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.0	0.0
Money Market Funds [Member] \| Level 3 [Member]
Investments, Fair Value Disclosure	0.0	0.0
Money Market Funds [Member] \| Level 3 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.0	0.0
Money Market Funds [Member] \| Fair Value [Member]
Investments, Fair Value Disclosure	0.4	0.4
Money Market Funds [Member] \| Fair Value [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.4	0.4
Equity Securities [Member] \| Level 1 [Member]
Investments, Fair Value Disclosure	0.0	0.0
Equity Securities [Member] \| Level 1 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.0	0.0
Equity Securities [Member] \| Level 2 [Member]
Investments, Fair Value Disclosure	3.6	5.1
Equity Securities [Member] \| Level 2 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	3.6	5.1
Equity Securities [Member] \| Level 3 [Member]
Investments, Fair Value Disclosure	0.0	0.0
Equity Securities [Member] \| Level 3 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.0	0.0
Equity Securities [Member] \| Fair Value [Member]
Investments, Fair Value Disclosure	3.6	5.1
Equity Securities [Member] \| Fair Value [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	3.6	5.1
Debt Securities [Member] \| Level 1 [Member]
Investments, Fair Value Disclosure	0.0	0.0
Debt Securities [Member] \| Level 1 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.0	0.0
Debt Securities [Member] \| Level 2 [Member]
Investments, Fair Value Disclosure	3.2	3.9
Debt Securities [Member] \| Level 2 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	3.2	3.9
Debt Securities [Member] \| Level 3 [Member]
Investments, Fair Value Disclosure	0.0	0.0
Debt Securities [Member] \| Level 3 [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	0.0	0.0
Debt Securities [Member] \| Fair Value [Member]
Investments, Fair Value Disclosure	3.2	3.9
Debt Securities [Member] \| Fair Value [Member] \| Subsidiaries [Member]
Investments, Fair Value Disclosure	3.2	3.9
Debt [Member] \| Level 1 [Member]
Debt	0.0	0.0
Debt [Member] \| Level 1 [Member] \| Subsidiaries [Member]
Debt	0.0	0.0
Debt [Member] \| Level 2 [Member]
Debt	1,346.0	1,502.5
Debt [Member] \| Level 2 [Member] \| Subsidiaries [Member]
Debt	610.0	625.4
Debt [Member] \| Level 3 [Member]
Debt	17.1	17.2
Debt [Member] \| Level 3 [Member] \| Subsidiaries [Member]
Debt	17.1	17.2
Debt [Member] \| Fair Value [Member]
Debt	1,363.1	1,519.7
Debt [Member] \| Fair Value [Member] \| Subsidiaries [Member]
Debt	$ 627.1	$ 642.6

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

+ Details

Name:	us-gaap_DebtInstrumentFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

Name:	us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ConsolidatedEntitiesAxis=srt_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_DebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: