Derivative Assets And Liabilities Table - Outstanding Commodity-Related Derivatives (Details)		Mar. 31, 2020 MMbtu barrels Megawatt bbl bushels	Dec. 31, 2019 MMbtu barrels Megawatt bbl bushels
Mark-To-Market Derivatives [Member] | Non Trading [Member] | Future [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | bushels		140
Natural Gas Liquids [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Forwards Swaps [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | bbl		2,235	1,300
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Basis Swaps IFERC/NYMEX [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		15,860	18,923
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Swing Swaps IFERC [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount			9,265
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Swing Swaps IFERC [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount		31,505
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Fixed Swaps/Futures [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		1,425	3,085
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Forward Physical Contracts [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		36,691	13,364
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Basis Swaps IFERC/NYMEX [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount	[1]	19,673	35,208
Natural Gas [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Fixed Swaps/Futures [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount		1,688	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		32,695	31,780
Natural Gas [Member] | Fair Value Hedging [Member] | Non Trading [Member] | Fixed Swaps/Futures [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount		32,695	31,780
Natural Gas [Member] | Fair Value Hedging [Member] | Non Trading [Member] | Hedged Item - Inventory (MMBtu) [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount		32,695	31,780
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Options - Puts [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		621,860
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Call Option [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | Megawatt			2,704,330
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Call Option [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		4,035,972
Power [Member] | Mark-To-Market Derivatives [Member] | Trading [Member] | Forwards Swaps [Member] | Long [Member]
Derivative, Nonmonetary Notional Amount | Megawatt		2,125,200	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		329,896
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		5,260	4,465
Refined product sales | Mark-To-Market Derivatives [Member] | Non Trading [Member] | Future [Member] | Short [Member]
Derivative, Nonmonetary Notional Amount | barrels		1,779	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