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