Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document Information [Table] Document Information [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] 5.5% Senior Notes due June 1, 2027 [Member] 5.5% Senior Notes due June 1, 2027 [Member] 5.5% Senior Notes due June 1, 2027 [Member] 5.875% Senior Notes due January 15, 2024 [Member] 5.875% Senior Notes due January 15, 2024 [Member] 5.875% Senior Notes due January 15, 2024 [Member] 4.25% Senior Notes due March 15, 2023 [Member] 4.25% Senior Notes due March 15, 2023 [Member] 4.25% Senior Notes due March 15, 2023 [Member] 7.50% Senior Notes Due 2020 [Member] 7.50% Senior Notes Due 2020 [Member] 7.50% Senior Notes Due 2020 [Member] Series E Preferred Units [Member] Series E Preferred Units [Member] Series E Preferred Units [Member] Series D Preferred Units [Member] Series D Preferred Units [Member] Series D Preferred Units [Member] Series C Preferred Units [Member] Series C Preferred Units [Member] Series C Preferred Units [Member] Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] Exchange [Domain] Exchange [Domain] NEW YORK STOCK EXCHANGE, INC. [Member] NEW YORK STOCK EXCHANGE, INC. [Member] Document Information, Document [Axis] Document Information, Document [Axis] Document [Domain] Document [Domain] Document Information [Line Items] Document Information [Line Items] Title of 12(b) Security Title of 12(b) Security Document Period End Date Document Period End Date Document Type Document Type Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Written Communications Written Communications Soliciting Material Soliciting Material Pre-commencement Tender Offer Pre-commencement Tender Offer Pre-commencement Issuer Tender Offer Pre-commencement Issuer Tender Offer Entity Emerging Growth Company Entity Emerging Growth Company Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity File Number Entity File Number Entity Tax Identification Number Entity Tax Identification Number Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Amendment Flag Amendment Flag Entity Central Index Key Entity Central Index Key