Goodwill and Other Intangibles - Components of Intangible Assets Subject to Amortization (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	$ 2,025	$ 2,051
Purchases	348	70
Acquisition of businesses	2,352	22
Usage/Sales/Retirements	(365)	(35)
Write-off of fully amortized balances	(216)	(74)
Impairment		(14)
Other	3	5
Balance at end of period	4,147	2,025
Less accumulated amortization	(1,636)	(1,357)
Net carrying amount	2,511	668
Renewable Energy Program
Finite-lived Intangible Assets [Roll Forward]
Carrying value	123	28
Emission Allowances
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	672	662
Purchases	10	25
Acquisition of businesses	0	0
Usage/Sales/Retirements	(1)	0
Write-off of fully amortized balances	(51)	(4)
Impairment		(14)
Other	4	3
Balance at end of period	634	672
Less accumulated amortization	(536)	(563)
Net carrying amount	98	109
Customer and Supply Contracts
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	28	28
Purchases	0	0
Acquisition of businesses	610	0
Usage/Sales/Retirements	0	0
Write-off of fully amortized balances	0	0
Impairment		0
Other	0	0
Balance at end of period	638	28
Less accumulated amortization	(94)	(28)
Net carrying amount	544	0
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	527	573
Purchases	0	0
Acquisition of businesses	1,308	22
Usage/Sales/Retirements	0	0
Write-off of fully amortized balances	(158)	(70)
Impairment		0
Other	2	2
Balance at end of period	1,679	527
Less accumulated amortization	(518)	(349)
Net carrying amount	$ 1,161	$ 178
Weighted average useful life, years	12 years	5 years
Marketing Partnerships
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	$ 285	$ 285
Purchases	0	0
Acquisition of businesses	0	0
Usage/Sales/Retirements	0	0
Write-off of fully amortized balances	0	0
Impairment		0
Other	(1)	0
Balance at end of period	284	285
Less accumulated amortization	(123)	(99)
Net carrying amount	161	186
Trade Names
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	373	373
Purchases	0	0
Acquisition of businesses	310	0
Usage/Sales/Retirements	0	0
Write-off of fully amortized balances	0	0
Impairment		0
Other	0	0
Balance at end of period	683	373
Less accumulated amortization	(294)	(247)
Net carrying amount	389	126
Other
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period	140	130
Purchases	338	45
Acquisition of businesses	124	0
Usage/Sales/Retirements	(364)	(35)
Write-off of fully amortized balances	(7)	0
Impairment		0
Other	(2)	0
Balance at end of period	229	140
Less accumulated amortization	(71)	(71)
Net carrying amount	$ 158	$ 69