Common Stock, $6.50 par value Common Stock [Member] Entity Tax Identification Number Entity Tax Identification Number Entity File Number Entity File Number Preferred Stock 2 Preferred Stock 2 [Member] Preferred Stock 2 Cover [Abstract] Cover [Abstract] Title of 12(b) Security Title of 12(b) Security Entities [Table] Entities [Table] Local Phone Number Local Phone Number Equity Component [Domain] Equity Component [Domain] Soliciting Material Soliciting Material Entity Address, Address Line One Entity Address, Address Line One 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] The NASDAQ Stock Market LLC NASDAQ - ALL MARKETS [Member] Trading Symbol Trading Symbol Exchange [Domain] Exchange [Domain] Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] City Area Code City Area Code Equity Components [Axis] Equity Components [Axis] Document Period End Date Document Period End Date Amendment Flag Amendment Flag Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Address, City or Town Entity Address, City or Town Security Exchange Name Security Exchange Name Document Type Document Type Pre-commencement Tender Offer Pre-commencement Tender Offer Entity Central Index Key Entity Central Index Key Entity Emerging Growth Company Entity Emerging Growth Company