Employee Benefit Plans - PAC - Unrecognized Amounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	$ (158)	$ (88)
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 | PAC
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	(53)	(42)
Regulatory deferrals	0	0
Total	(53)	(42)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	(42)
Ending balance	(53)	(42)
Other Postretirement | PAC | Regulatory Liability
Defined Benefit Plan Disclosure [Line Items]
Total	(53)	(42)
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	(42)	(35)
Net gain arising during the year	(13)	(9)
Net amortization	2	2
Total	(11)	(7)
Ending balance	(53)	(42)
U.S. | Pension
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	283	325
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 amortization	(9)	(14)
Total	(47)	(46)
Ending balance	297	344
U.S. | Pension | PAC
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	258	270
Regulatory deferrals	19	22
Total	277	292
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	292	302
Net gain arising during the year	(6)	2
Net amortization	(9)	(12)
Total	(15)	(10)
Ending balance	277	292
U.S. | Pension | PAC | Regulatory Asset
Defined Benefit Plan Disclosure [Line Items]
Total	265	279
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	279	290
Net gain arising during the year	(5)	0
Net amortization	(9)	(11)
Total	(14)	(11)
Ending balance	265	279
U.S. | Pension | PAC | Accumulated Other Comprehensive Income (Loss)
Defined Benefit Plan Disclosure [Line Items]
Total	12	13
Defined Benefit Plan, Reconciliation of Amounts Not Yet Recognized As Components of Net Periodic Benefit Cost [Roll Forward]
Beginning balance	13	12
Net gain arising during the year	(1)	2
Net amortization	0	(1)
Total	(1)	1
Ending balance	$ 12	$ 13