Document Information [Table] Legal Entity [Axis] Entity [Domain] Class of Stock [Axis] Class of Stock [Domain] Class A Common Stock 001 Par Value Per Share Custom [Member] Preferred Stock Purchase Rights1 Custom [Member] Depositary Shares Each Representing 11000th Of A Share Of 7625 Series A Preferred Stock Custom [Member] Document Information [Line Items] Entity, Registrant Name Document, Type Document, Period End Date Entity, Incorporation, State or Country Code Entity, File Number Entity, Tax Identification Number Entity, Address, Address Line One Entity, Address, City or Town Entity, Address, State or Province Entity, Address, Postal Zip Code City Area Code Local Phone Number Written Communications Soliciting Material Pre-commencement Tender Offer Pre-commencement Issuer Tender Offer Title of 12(b) Security Trading Symbol No Trading Symbol Flag Security Exchange Name Entity, Emerging Growth Company Amendment Flag Entity, Central Index Key