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