Written Communications Written Communications Soliciting Material Soliciting Material Common Shares Common Class B [Member] Local Phone Number Local Phone Number Class of Stock [Domain] Class of Stock [Domain] 6.25% Senior Notes Six Point Two Five Percent 2069 Senior Notes [Member] Six Point Two Five Percent 2069 Senior Notes [Member] Amendment Flag Amendment Flag Entity Emerging Growth Company Entity Emerging Growth Company Entity File Number Entity File Number Security Exchange Name Security Exchange Name Entity Address, State or Province Entity Address, State or Province Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Address, Address Line One Entity Address, Address Line One City Area Code City Area Code 5.50% Senior Notes Five Point Five Percent June 2070 Senior Notes [Member] Five Point Five Percent June 2070 Senior Notes Document Period End Date Document Period End Date 5.50% Senior Notes Five Point Five Percent 2070 Senior Notes [Member] Five Point Five Percent 2070 Senior Notes Pre-commencement Tender Offer Pre-commencement Tender Offer Class of Stock [Axis] Class of Stock [Axis] Entity Central Index Key Entity Central Index Key Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Tax Identification Number Entity Tax Identification Number Statement [Line Items] Statement [Line Items] Entity Registrant Name Entity Registrant Name Trading Symbol Trading Symbol Statement [Table] Statement [Table] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Title of 12(b) Security Title of 12(b) Security Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Address, City or Town Entity Address, City or Town Document Type Document Type