Employee Benefit Plans - Unrecognized Amounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Pension | U.S.
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	$ 283	$ 325
Prior service (credit) cost	(5)	(3)
Regulatory deferrals	19	22
Total	297	344
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	344	390
Net gain arising during the year	(35)	(35)
Net prior service credit arising during the year	(3)
Settlement		3
Net amortization	(9)	(14)
Total	(47)	(46)
Ending balance	297	344
Pension | U.S. | Accumulated Other Comprehensive Income (Loss)
Defined Benefit Plan Disclosure [Line Items]
Total	(6)	(1)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	(1)	0
Net gain arising during the year	(5)	0
Net prior service credit arising during the year	0
Settlement		0
Net amortization	0	(1)
Total	(5)	(1)
Ending balance	(6)	(1)
Pension | U.S. | Regulatory Asset (Liability)
Defined Benefit Plan Disclosure [Line Items]
Total	303	345
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	345	390
Net gain arising during the year	(30)	(35)
Net prior service credit arising during the year	(3)
Settlement		3
Net amortization	(9)	(13)
Total	(42)	(45)
Ending balance	303	345
Pension | United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Net loss	541	532
Prior service cost	40	44
Total	581	576
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	576
Ending balance	581	576
Pension | United Kingdom | Accumulated Other Comprehensive Income (Loss)
Defined Benefit Plan Disclosure [Line Items]
Total	581	576
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	576	529
Net gain arising during the year	44	29
Net prior service credit arising during the year	0	16
Net amortization	(29)	(26)
Foreign currency exchange rate changes	(10)	28
Total	5	47
Ending balance	581	576
Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	(158)	(88)
Prior service (credit) cost	18	20
Regulatory deferrals	0	0
Total	(140)	(68)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	(68)	(16)
Net gain arising during the year	(73)	(54)
Net amortization	1	2
Total	(72)	(52)
Ending balance	(140)	(68)
Other Postretirement | Accumulated Other Comprehensive Income (Loss)
Defined Benefit Plan Disclosure [Line Items]
Total	(10)	(5)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	(5)	(2)
Net gain arising during the year	(5)	(3)
Net amortization	0	0
Total	(5)	(3)
Ending balance	(10)	(5)
Other Postretirement | Regulatory Asset (Liability)
Defined Benefit Plan Disclosure [Line Items]
Total	(130)	(63)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	(63)	(14)
Net gain arising during the year	(68)	(51)
Net amortization	1	2
Total	(67)	(49)
Ending balance	$ (130)	$ (63)