Investments Equity investments (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity Investments	$ 7,759.0	$ 7,481.0
Earnings (Losses) from Equity Investments	101.0	617.0	$ 428.0
Amortization of excess costs	(83.0)	(95.0)	(61.0)
Notes Payable, Related Parties, Noncurrent	$ 157.0	148.0
Citrus Corporation
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 1,856.0	1,708.0
Earnings (Losses) from Equity Investments	$ 157.0	169.0	108.0
SNG
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 1,473.0	1,536.0
Earnings (Losses) from Equity Investments	$ 140.0	141.0	77.0
NGPL Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 721.0	733.0
Earnings (Losses) from Equity Investments	81.0	66.0	10.0
Notes Receivable, Related Parties, Noncurrent	500.0
Notes Payable, Related Parties, Noncurrent	$ 500.0
Debt Instrument, Interest Rate, Stated Percentage	6.75%
NGPL Holdings, LLC \| Earnings from Equity Investments
Schedule of Equity Method Investments [Line Items]
Interest	$ 8.4
Gulf Coast Express LLC
Schedule of Equity Method Investments [Line Items]
Ownership Interest	34.00%
Equity Investments	$ 656.0	240.0
Earnings (Losses) from Equity Investments	$ 37.0	2.0	0.0
MEP
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 439.0	235.0
Earnings (Losses) from Equity Investments	$ 15.0	31.0	38.0
Gulf LNG Holdings Group LLC
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 361.0	361.0
Earnings (Losses) from Equity Investments	$ 17.0	(61.0)	47.0
Equity Method Investment, Other than Temporary Impairment		270.0
Plantation Pipe Line Company
Schedule of Equity Method Investments [Line Items]
Ownership Interest	51.00%
Equity Investments	$ 348.0	344.0
Earnings (Losses) from Equity Investments	$ 58.0	55.0	46.0
Utopia Holding L.L.C.
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 335.0	333.0
Earnings (Losses) from Equity Investments	$ 20.0	14.0	0.0
Permian Highway Pipeline
Schedule of Equity Method Investments [Line Items]
Ownership Interest	27.00%
Equity Investments	$ 309.0	45.0
Earnings (Losses) from Equity Investments	$ 0.0	0.0	0.0
EagleHawk
Schedule of Equity Method Investments [Line Items]
Ownership Interest	25.00%
Equity Investments	$ 285.0	299.0
Earnings (Losses) from Equity Investments	17.0	7.0	24.0
Watco Companies, LLC
Schedule of Equity Method Investments [Line Items]
Equity Investments	185.0	185.0
Earnings (Losses) from Equity Investments	$ 19.0	21.0	19.0
Common Unit, Issued	13,000
Watco Companies, LLC \| Preferred stock
Schedule of Equity Method Investments [Line Items]
Common Unit, Issued	100,000
Quarterly preferred distribution rate	3.25%
Watco Companies, LLC \| Preferred Class B
Schedule of Equity Method Investments [Line Items]
Common Unit, Issued	50,000
Quarterly preferred distribution rate	3.00%
Watco Companies, LLC \| Common Units
Schedule of Equity Method Investments [Line Items]
Ownership Interest	3.00%
FEP
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 102.0	44.0
Earnings (Losses) from Equity Investments	$ 59.0	55.0	(97.0)
Equity Method Investment, Other than Temporary Impairment			150.0
Ruby
Schedule of Equity Method Investments [Line Items]
Ownership Interest	50.00%
Equity Investments	$ 41.0	750.0
Earnings (Losses) from Equity Investments	(609.0)	26.0	44.0
Equity Method Investment, Other than Temporary Impairment	$ 650.0
Cortez Pipeline Company
Schedule of Equity Method Investments [Line Items]
Ownership Interest	53.00%
Equity Investments	$ 26.0	15.0
Earnings (Losses) from Equity Investments	35.0	36.0	44.0
All others
Schedule of Equity Method Investments [Line Items]
Equity Investments	622.0	653.0
Earnings (Losses) from Equity Investments	$ 55.0	$ 55.0	$ 68.0

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