Common Stock 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 Legal Entity [Axis] Legal Entity [Axis] Cover page. Cover [Abstract] Title of 12(b) Security Title of 12(b) Security Entities [Table] Entities [Table] Local Phone Number Local Phone Number NEW YORK STOCK EXCHANGE, INC. NEW YORK STOCK EXCHANGE, INC. [Member] Class of Stock [Domain] Class of Stock [Domain] Entity Address, Address Line One Entity Address, Address Line One Written Communications 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 Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Written Communications Written Communications Entity Information [Line Items] Entity Information [Line Items] Trading Symbol Trading Symbol Exchange [Domain] Exchange [Domain] Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] City Area Code City Area Code Series A Preferred Stock Series A Preferred Stock [Member] Document Period End Date Document Period End Date NYSE TEXAS, INC. NYSE TEXAS, INC. [Member] Amendment Flag Amendment Flag Entity Address, City or Town Entity Address, City or Town Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity [Domain] Entity [Domain] Security Exchange Name Security Exchange Name Document Type Document Type Class of Stock [Axis] Class of Stock [Axis] Pre-commencement Tender Offer Pre-commencement Tender Offer Entity Central Index Key Entity Central Index Key Entity Emerging Growth Company Entity Emerging Growth Company