Pension and Postretirement Benefit Costs - Narrative (Details) $ in Millions	Jun. 30, 2022 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Liability for Future Policy Benefits, Individual and Group Annuities and Supplementary Contracts	$ 500.0
Defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Funding threshold	80.00%

Amount of accrued obligation to policyholders that relates to insured events under individual and group annuities and supplementary insurance contracts.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 25
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=124504495&loc=d3e13145-158430

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(a)(1))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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