Derivatives and Risk Management (Summary of Before Tax Effect of Fair Value Hedges not Designated for Hedge Accounting) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	$ (3,237)	$ (169)
Total loss on settled derivatives	(695)	(22)
Non-performance risk adjustment	5	0
Total loss on derivatives	(3,927)	(191)
Fixed price swaps | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(1,853)	(22)
Total loss on settled derivatives	(297)	5
Fixed price swaps | Oil
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(53)	(40)
Total loss on settled derivatives	(33)	(17)
Fixed price swaps | Ethane
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(21)	(2)
Total loss on settled derivatives	(8)	(4)
Fixed price swaps | Propane
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(49)	(45)
Total loss on settled derivatives	(41)	(30)
Fixed price swaps | Normal Butane
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(20)	(15)
Total loss on settled derivatives	(14)	(7)
Fixed price swaps | Natural Gasoline
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(28)	(20)
Total loss on settled derivatives	(19)	(9)
Two-way costless collars | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(342)	(12)
Total loss on settled derivatives	(104)	2
Two-way costless collars | Oil
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	0	(1)
Total loss on settled derivatives	0	(1)
Two-way costless collars | Ethane
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	1	0
Total loss on settled derivatives	(1)	0
Three-way costless collars | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(724)	0
Total loss on settled derivatives	(121)	1
Three-way costless collars | Oil
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(33)	(18)
Total loss on settled derivatives	(13)	(1)
Three-way costless collars | Propane
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(2)	(1)
Total loss on settled derivatives	(2)	0
Basis swaps | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	36	3
Total loss on settled derivatives	1	41
Call options | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(149)	3
Total loss on settled derivatives	(39)	0
Call options | Oil
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	0	(1)
Put options | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on settled derivatives	0	(2)
Amortization of premium paid		2
Swaptions | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	0	1
Purchased fixed price swaps | Natural Gas Storage
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	1	0
Fixed price swaps – storage | Natural Gas Storage
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	1	0
Total loss on settled derivatives	(3)	0
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on unsettled derivatives	(2)	1
Index swap | Natural Gas
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on settled derivatives	$ (1)	$ 0