Common shares Common Stock [Member] Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line Two Entity Address, Address Line Two Entity File Number Entity File Number Title of 12(b) Security Title of 12(b) Security Class of Stock [Domain] Class of Stock [Domain] Local Phone Number Local Phone Number Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Series G Depositary Share Equivalent Series G Depositary Share Equivalent [Member] Series G Depositary Share Equivalent Soliciting Material Soliciting Material Entity Address, Address Line One Entity Address, Address Line One Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Written Communications Written Communications Entity Listings [Line Items] Entity Listings [Line Items] Trading Symbol Trading Symbol City Area Code City Area Code Entity Listings [Table] Entity Listings [Table] Document Period End Date Document Period End Date Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Address, City or Town Entity Address, City or Town Amendment Flag Amendment Flag Entity Address, Country Entity Address, Country Security Exchange Name Security Exchange Name Class of Stock [Axis] Class of Stock [Axis] Document Type Document Type Series F Depositary Share Equivalent Series F Depositary Share Equivalent [Member] Series F Depositary Share Equivalent Pre-commencement Tender Offer Pre-commencement Tender Offer Entity Central Index Key Entity Central Index Key Entity Emerging Growth Company Entity Emerging Growth Company