Debt Obligations (Details) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Debt Instrument [Line Items]      
Principal outstanding $ 24,163.0   $ 22,738.5
Other, non-principal amounts (203.7)   (197.7)
Less current maturities of debt (2,838.1)   (1,863.9)
Total long-term debt 21,121.2   20,676.9
Debt Obligations Terms [Abstract]      
Repayment of debt obligations 48,776.5 $ 16,139.2  
Letters of credit outstanding 67.7    
Total unamortized debt issuance costs     149.8
Senior Debt Obligations [Member]      
Debt Instrument [Line Items]      
Principal outstanding 22,688.6   21,264.1
Debt Obligations Terms [Abstract]      
Aggregate debt principal issued 1,250.0    
Senior Debt Obligations [Member] | Commercial Paper Notes [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 2,038.6   1,114.1
Debt Obligations Terms [Abstract]      
Interest rate terms variable    
Information regarding variable interest rates paid [Abstract]      
Weighted-average interest rate paid 0.89%    
Senior Debt Obligations [Member] | Commercial Paper Notes [Member] | Minimum [Member]      
Information regarding variable interest rates paid [Abstract]      
Variable interest rates paid 0.56%    
Senior Debt Obligations [Member] | Commercial Paper Notes [Member] | Maximum [Member]      
Information regarding variable interest rates paid [Abstract]      
Variable interest rates paid 1.18%    
Senior Debt Obligations [Member] | EPO Senior Notes AA [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 0.0   750.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 3.20%    
Maturity date Feb. 01, 2016    
Repayment of debt obligations $ 750.0    
Senior Debt Obligations [Member] | EPO Senior Notes L [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 800.0   800.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.30%    
Maturity date Sep. 01, 2017    
Senior Debt Obligations [Member] | EPO 364-Day Credit Agreement [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 0.0   0.0
Debt Obligations Terms [Abstract]      
Interest rate terms variable    
Maturity date Sep. 14, 2017    
Maximum borrowing capacity $ 1,500.0    
Maximum bank commitments increase 200.0    
Total maximum borrowing capacity 1,700.0    
Senior Debt Obligations [Member] | EPO Senior Notes V [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 349.7   349.7
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.65%    
Maturity date Apr. 15, 2018    
Senior Debt Obligations [Member] | EPO Senior Notes OO [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 750.0   750.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 1.65%    
Maturity date May 07, 2018    
Senior Debt Obligations [Member] | EPO Senior Notes N [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 700.0   700.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.50%    
Maturity date Jan. 31, 2019    
Senior Debt Obligations [Member] | EPO Senior Notes LL [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 800.0   800.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 2.55%    
Maturity date Oct. 15, 2019    
Senior Debt Obligations [Member] | EPO Senior Notes Q [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 500.0   500.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 5.25%    
Maturity date Jan. 31, 2020    
Senior Debt Obligations [Member] | EPO Senior Notes Y [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 1,000.0   1,000.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 5.20%    
Maturity date Sep. 01, 2020    
Senior Debt Obligations [Member] | EPO Multi-Year Revolving Credit Facility [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 0.0   0.0
Debt Obligations Terms [Abstract]      
Interest rate terms variable    
Maturity date Sep. 15, 2020    
Information regarding variable interest rates paid [Abstract]      
Weighted-average interest rate paid 1.43%    
Senior Debt Obligations [Member] | EPO Multi-Year Revolving Credit Facility [Member] | Minimum [Member]      
Information regarding variable interest rates paid [Abstract]      
Variable interest rates paid 1.43%    
Senior Debt Obligations [Member] | EPO Multi-Year Revolving Credit Facility [Member] | Maximum [Member]      
Information regarding variable interest rates paid [Abstract]      
Variable interest rates paid 1.43%    
Senior Debt Obligations [Member] | EPO Senior Notes RR [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 575.0   0.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 2.85%    
Maturity date Apr. 15, 2021    
Aggregate debt principal issued $ 575.0    
Debt issued as percent of principal amount 99.898%    
Senior Debt Obligations [Member] | EPO Senior Notes CC [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 650.0   650.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 4.05%    
Maturity date Feb. 15, 2022    
Senior Debt Obligations [Member] | EPO Senior Notes HH [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 1,250.0   1,250.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 3.35%    
Maturity date Mar. 15, 2023    
Senior Debt Obligations [Member] | EPO Senior Notes JJ [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 850.0   850.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 3.90%    
Maturity date Feb. 15, 2024    
Senior Debt Obligations [Member] | EPO Senior Notes MM [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 1,150.0   1,150.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 3.75%    
Maturity date Feb. 15, 2025    
Senior Debt Obligations [Member] | EPO Senior Notes PP [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 875.0   875.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 3.70%    
Maturity date Feb. 15, 2026    
Senior Debt Obligations [Member] | EPO Senior Notes SS [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 575.0   0.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 3.95%    
Maturity date Feb. 15, 2027    
Aggregate debt principal issued $ 575.0    
Debt issued as percent of principal amount 99.76%    
Senior Debt Obligations [Member] | EPO Senior Notes D [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 500.0   500.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.875%    
Maturity date Mar. 01, 2033    
Senior Debt Obligations [Member] | EPO Senior Notes H [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 350.0   350.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.65%    
Maturity date Oct. 15, 2034    
Senior Debt Obligations [Member] | EPO Senior Notes J [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 250.0   250.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 5.75%    
Maturity date Mar. 01, 2035    
Senior Debt Obligations [Member] | EPO Senior Notes W [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 399.6   399.6
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 7.55%    
Maturity date Apr. 15, 2038    
Senior Debt Obligations [Member] | EPO Senior Notes R [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 600.0   600.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.125%    
Maturity date Oct. 15, 2039    
Senior Debt Obligations [Member] | EPO Senior Notes Z [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 600.0   600.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.45%    
Maturity date Sep. 01, 2040    
Senior Debt Obligations [Member] | EPO Senior Notes BB [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 750.0   750.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 5.95%    
Maturity date Feb. 01, 2041    
Senior Debt Obligations [Member] | EPO Senior Notes DD [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 600.0   600.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 5.70%    
Maturity date Feb. 15, 2042    
Senior Debt Obligations [Member] | EPO Senior Notes EE [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 750.0   750.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 4.85%    
Maturity date Aug. 15, 2042    
Senior Debt Obligations [Member] | EPO Senior Notes GG [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 1,100.0   1,100.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 4.45%    
Maturity date Feb. 15, 2043    
Senior Debt Obligations [Member] | EPO Senior Notes II [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 1,400.0   1,400.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 4.85%    
Maturity date Mar. 15, 2044    
Senior Debt Obligations [Member] | EPO Senior Notes KK [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 1,150.0   1,150.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 5.10%    
Maturity date Feb. 15, 2045    
Senior Debt Obligations [Member] | EPO Senior Notes QQ [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 975.0   875.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 4.90%    
Maturity date May 15, 2046    
Aggregate debt principal issued $ 100.0    
Debt issued as percent of principal amount 95.516%    
Senior Debt Obligations [Member] | EPO Senior Notes NN [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 400.0   400.0
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 4.95%    
Maturity date Oct. 15, 2054    
Senior Debt Obligations [Member] | TEPPCO Senior Notes 4 [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 0.3   0.3
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 6.65%    
Maturity date Apr. 15, 2018    
Senior Debt Obligations [Member] | TEPPCO Senior Notes 5 [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 0.4   0.4
Debt Obligations Terms [Abstract]      
Interest rate terms fixed    
Interest rate, stated percentage 7.55%    
Maturity date Apr. 15, 2038    
Junior Debt Obligations [Member] | EPO Junior Subordinated Notes A [Member]      
Debt Instrument [Line Items]      
Principal outstanding [1] $ 521.1   521.1
Debt Obligations Terms [Abstract]      
Interest rate terms [1] fixed/variable    
Interest rate, stated percentage 8.375%    
Maturity date [1] Aug. 31, 2066    
Variable annual interest rate thereafter, variable rate basis 3-month LIBOR    
Variable interest rate 3.708%    
Information regarding variable interest rates paid [Abstract]      
Weighted-average interest rate paid 4.46%    
Junior Debt Obligations [Member] | EPO Junior Subordinated Notes A [Member] | Minimum [Member]      
Information regarding variable interest rates paid [Abstract]      
Variable interest rates paid 4.46%    
Junior Debt Obligations [Member] | EPO Junior Subordinated Notes A [Member] | Maximum [Member]      
Information regarding variable interest rates paid [Abstract]      
Variable interest rates paid 4.46%    
Junior Debt Obligations [Member] | EPO Junior Subordinated Notes C [Member]      
Debt Instrument [Line Items]      
Principal outstanding [2] $ 256.4   256.4
Debt Obligations Terms [Abstract]      
Interest rate terms [2] fixed/variable    
Interest rate, stated percentage 7.00%    
Maturity date [2] Jun. 01, 2067    
Variable annual interest rate thereafter, variable rate basis 3-month LIBOR    
Variable interest rate 2.778%    
Junior Debt Obligations [Member] | EPO Junior Subordinated Notes B [Member]      
Debt Instrument [Line Items]      
Principal outstanding [3] $ 682.7   682.7
Debt Obligations Terms [Abstract]      
Interest rate terms [3] fixed/variable    
Interest rate, stated percentage 7.034%    
Maturity date [3] Jan. 15, 2068    
Variable annual interest rate thereafter, variable rate basis 3-month LIBOR    
Variable interest rate 2.68%    
Minimum variable annual interest rate 7.034%    
Junior Debt Obligations [Member] | TEPPCO Junior Subordinated Notes [Member]      
Debt Instrument [Line Items]      
Principal outstanding $ 14.2   $ 14.2
Debt Obligations Terms [Abstract]      
Interest rate terms fixed/variable    
Maturity date Jun. 01, 2067    
[1] Fixed rate of 8.375% was paid through August 1, 2016; thereafter, a variable rate is in effect based on 3-month LIBOR plus 3.708%.
[2] Fixed rate of 7.000% through September 1, 2017 (i.e., first call date without a make-whole redemption premium); thereafter, variable rate based on 3-month LIBOR plus 2.778%.
[3] Fixed rate of 7.034% through January 15, 2018 (i.e., first call date without a make-whole redemption premium); thereafter, the rate will be the greater of 7.034% or a variable rate based on 3-month LIBOR plus 2.680%.