Fair Value Measurements, Recurring (Details) - Fair Value, Recurring [Member] - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Assets
Investments in AFS debt securities	$ 26	$ 111
Total gross fair value, assets	529	994
Effect of counterparty netting	(402)	(642)
Effect of cash collateral netting	0	(66)
Net carrying value on balance sheet, assets	127	286
Liabilities
Blending program obligations	13	58
Total gross fair value, liabilities	464	714
Effect of counterparty netting	(402)	(642)
Effect of cash collateral netting	(46)	(1)
Net carrying value on balance sheet, liabilities	16	71
Assets Held in Trust [Member]
Assets
Investments of certain benefit plans	93	80
Commodity Contracts [Member]
Assets
Derivative contracts	402	803
Effect of counterparty netting	(402)	(642)
Effect of cash collateral netting	0	(66)
Derivative contracts, net assets	0	95
Cash collateral received not offset	0	0
Liabilities
Derivative contracts	448	643
Effect of counterparty netting	(402)	(642)
Effect of cash collateral netting	(46)	(1)
Derivative contracts, net liabilities	0	0
Cash collateral paid not offset	(71)	(67)
Physical Purchase Contracts [Member]
Assets
Derivative assets, not subject to netting	2
Liabilities
Derivative liabilities, not subject to netting	3	6
Foreign Currency Contracts [Member]
Assets
Derivative assets, not subject to netting	6
Liabilities
Derivative liabilities, not subject to netting		7
Fair Value, Inputs, Level 1 [Member]
Assets
Investments in AFS debt securities	6	36
Total gross fair value, assets	503	915
Liabilities
Blending program obligations	0	0
Total gross fair value, liabilities	448	650
Fair Value, Inputs, Level 1 [Member] | Assets Held in Trust [Member]
Assets
Investments of certain benefit plans	89	76
Fair Value, Inputs, Level 1 [Member] | Commodity Contracts [Member]
Assets
Derivative contracts	402	803
Liabilities
Derivative contracts	448	643
Fair Value, Inputs, Level 1 [Member] | Physical Purchase Contracts [Member]
Assets
Derivative assets, not subject to netting	0
Liabilities
Derivative liabilities, not subject to netting	0	0
Fair Value, Inputs, Level 1 [Member] | Foreign Currency Contracts [Member]
Assets
Derivative assets, not subject to netting	6
Liabilities
Derivative liabilities, not subject to netting		7
Fair Value, Inputs, Level 2 [Member]
Assets
Investments in AFS debt securities	20	75
Total gross fair value, assets	22	75
Liabilities
Blending program obligations	13	58
Total gross fair value, liabilities	16	64
Fair Value, Inputs, Level 2 [Member] | Assets Held in Trust [Member]
Assets
Investments of certain benefit plans	0	0
Fair Value, Inputs, Level 2 [Member] | Commodity Contracts [Member]
Assets
Derivative contracts	0	0
Liabilities
Derivative contracts	0	0
Fair Value, Inputs, Level 2 [Member] | Physical Purchase Contracts [Member]
Assets
Derivative assets, not subject to netting	2
Liabilities
Derivative liabilities, not subject to netting	3	6
Fair Value, Inputs, Level 2 [Member] | Foreign Currency Contracts [Member]
Assets
Derivative assets, not subject to netting	0
Liabilities
Derivative liabilities, not subject to netting		0
Fair Value, Inputs, Level 3 [Member]
Assets
Investments in AFS debt securities	0	0
Total gross fair value, assets	4	4
Liabilities
Blending program obligations	0	0
Total gross fair value, liabilities	0	0
Fair Value, Inputs, Level 3 [Member] | Assets Held in Trust [Member]
Assets
Investments of certain benefit plans	4	4
Fair Value, Inputs, Level 3 [Member] | Commodity Contracts [Member]
Assets
Derivative contracts	0	0
Liabilities
Derivative contracts	0	0
Fair Value, Inputs, Level 3 [Member] | Physical Purchase Contracts [Member]
Assets
Derivative assets, not subject to netting	0
Liabilities
Derivative liabilities, not subject to netting	0	0
Fair Value, Inputs, Level 3 [Member] | Foreign Currency Contracts [Member]
Assets
Derivative assets, not subject to netting	$ 0
Liabilities
Derivative liabilities, not subject to netting		$ 0