Soliciting Material Soliciting Material Written Communications Written Communications Local Phone Number Local Phone Number Class of Stock [Domain] Class of Stock [Domain] 2025 Series H 6.25% Junior Subordinated Debentures due 2085 Series H, 2025, 6.25% Junior Subordinated Debentures Due 2085 [Member] Series H, 2025, 6.25% Junior Subordinated Debentures Due 2085 Amendment Flag Amendment Flag 2017 Series E 5.25% Junior Subordinated Debentures due 2077 Series E, 2017, 5.25% Junior Subordinated Debentures Due 2077 [Member] Series E, 2017, 5.25% Junior Subordinated Debentures Due 2077 [Member] Entity Emerging Growth Company Entity Emerging Growth Company 2020 Series G 4.375% Junior Subordinated Debentures due 2080 Series G, 2020, 4.375% Junior Subordinated Debentures Due 2080 [Member] Series G, 2020, 4.375% Junior Subordinated Debentures Due 2080 Entity File Number Entity File Number Security Exchange Name Security Exchange Name Entity Address, State or Province Entity Address, State or Province Entity Address, Address Line One Entity Address, Address Line One City Area Code City Area Code Cover [Abstract] Cover [Abstract] Entity Information [Line Items] Entity Information [Line Items] Document Period End Date Document Period End Date Pre-commencement Tender Offer Pre-commencement Tender Offer Class of Stock [Axis] Class of Stock [Axis] Entity Central Index Key Entity Central Index Key Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Tax Identification Number Entity Tax Identification Number Entities [Table] Entities [Table] Entity Registrant Name Entity Registrant Name Trading Symbol Trading Symbol Common stock, without par value Common Stock [Member] 2021 Series E 4.375% Junior Subordinated Debentures due 2081 Series E, 2021, 4.375% Junior Subordinated Debentures Due 2081 [Member] Series E, 2021, 4.375% Junior Subordinated Debentures Due 2081 Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Title of 12(b) Security Title of 12(b) Security Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Address, City or Town Entity Address, City or Town Document Type Document Type