Class of Stock [Domain] Class of Stock [Domain] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] Series I Preferred Stock Series I Preferred Stock [Member] Series I Preferred Stock CHICAGO STOCK EXCHANGE, INC NYSE CHICAGO, INC. [Member] Class of Stock [Axis] Class of Stock [Axis] Security Exchange Name Security Exchange Name Entity Address, City or Town Entity Address, City or Town Soliciting Material Soliciting Material Cover [Abstract] Cover [Abstract] City Area Code City Area Code Common Stock Common Stock [Member] Amendment Flag Amendment Flag Entity Tax Identification Number Entity Tax Identification Number Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Pre-commencement Tender Offer Pre-commencement Tender Offer Entity Emerging Growth Company Entity Emerging Growth Company NEW YORK STOCK EXCHANGE, INC. NEW YORK STOCK EXCHANGE, INC. [Member] Entity Central Index Key Entity Central Index Key Entity File Number Entity File Number Entity Address, State or Province Entity Address, State or Province Series H Preferred Stock Series H Preferred Stock [Member] Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Address, Address Line One Entity Address, Address Line One Document Information [Line Items] Document Information [Line Items] Document Information [Table] Document Information [Table] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Written Communications Written Communications Local Phone Number Local Phone Number Exchange [Domain] Exchange [Domain] Title of 12(b) Security Title of 12(b) Security Document Period End Date Document Period End Date Document Type Document Type Subordinated Debentures Due 2053 at 5.10 Percent Subordinated Debentures Due 2053 at 5.10 Percent [Member] Represents the subordinated debentures due in 2053 at an interest rate of 5.10 percent. Series I Preferred Stock Series J Preferred Stock [Member] Series J Preferred Stock