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