Derivative Assets And Liabilities Table - Outstanding Commodity-Related Derivatives (Details)		Jun. 30, 2020 MMbtu barrels Megawatt bbl bushels	Dec. 31, 2019 MMbtu barrels Megawatt bbl bushels
Mark-To-Market Derivatives [Member] | Non Trading [Member] | Future [Member]
Derivative, Nonmonetary Notional Amount | bushels		0
Natural Gas Liquids [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Forwards Swaps [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | bbl		8,830	1,300
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Basis Swaps IFERC/NYMEX [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		27,713	18,923
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Swing Swaps IFERC [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		35,590	9,265
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Fixed Swaps/Futures [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		10,708	3,085
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Forward Physical Contracts [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		23,980	13,364
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Basis Swaps IFERC/NYMEX [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount	[1]	20,433	35,208
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Fixed Swaps/Futures [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount		373	1,483
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Options - Puts [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount		0
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Put Option [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount			0
Natural Gas [Member] | Fair Value Hedging [Member] | Non Trading [Member] | Basis Swaps IFERC/NYMEX [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		43,235	31,780
Natural Gas [Member] | Fair Value Hedging [Member] | Non Trading [Member] | Fixed Swaps/Futures [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		43,235	31,780
Natural Gas [Member] | Fair Value Hedging [Member] | Non Trading [Member] | Hedged Item - Inventory (MMBtu) [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount		43,235	31,780
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Options - Puts [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		340,743
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Call Option [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		1,268,532	2,704,330
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Forwards Swaps [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		1,338,776	3,213,450
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Future [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | Megawatt			353,527
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Future [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		204,090
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Put Option [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | Megawatt			51,615
Crude Oil [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Forwards Swaps [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | bbl		3,393	4,465
Refined product sales | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Future [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | barrels		3,370	2,473
Corn [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Future [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | bushels			1,210

[1] Includes aggregate amounts for open positions related to Houston Ship Channel, Waha Hub, NGPL TexOk, West Louisiana Zone and Henry Hub locations