Fair Value Measurements - Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - Commodity Contract - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Natural Gas | Natural Gas Swaps
Financial Assets:
Assets, fair value disclosure		$ 1
Natural Gas | Natural Gas Swaps | Quoted Prices in Active Markets (Level 1)
Financial Assets:
Assets, fair value disclosure		0
Natural Gas | Natural Gas Swaps | Significant Other Observable Inputs (Level 2)
Financial Assets:
Assets, fair value disclosure		1
Natural Gas | Natural Gas Swaps | Significant Unobservable Inputs (Level 3)
Financial Assets:
Assets, fair value disclosure		0
Natural Gas | Price Swaps
Financial Assets:
Assets, fair value disclosure	$ 16
Financial Liabilities:
Liabilities, fair value disclosure	36	117
Natural Gas | Price Swaps | Quoted Prices in Active Markets (Level 1)
Financial Assets:
Assets, fair value disclosure	0
Financial Liabilities:
Liabilities, fair value disclosure	0	0
Natural Gas | Price Swaps | Significant Other Observable Inputs (Level 2)
Financial Assets:
Assets, fair value disclosure	16
Financial Liabilities:
Liabilities, fair value disclosure	36	117
Natural Gas | Price Swaps | Significant Unobservable Inputs (Level 3)
Financial Assets:
Assets, fair value disclosure	0
Financial Liabilities:
Liabilities, fair value disclosure	0	0
Natural Gas | Collar
Financial Assets:
Assets, fair value disclosure	5
Financial Liabilities:
Liabilities, fair value disclosure	4
Natural Gas | Collar | Quoted Prices in Active Markets (Level 1)
Financial Assets:
Assets, fair value disclosure	0
Financial Liabilities:
Liabilities, fair value disclosure	0
Natural Gas | Collar | Significant Other Observable Inputs (Level 2)
Financial Assets:
Assets, fair value disclosure	5
Financial Liabilities:
Liabilities, fair value disclosure	4
Natural Gas | Collar | Significant Unobservable Inputs (Level 3)
Financial Assets:
Assets, fair value disclosure	0
Financial Liabilities:
Liabilities, fair value disclosure	0
Brent Crude Oil (Brent) Linked Gas Sales Contract
Financial Assets:
Assets, fair value disclosure	65
Brent Crude Oil (Brent) Linked Gas Sales Contract | Quoted Prices in Active Markets (Level 1)
Financial Assets:
Assets, fair value disclosure	0
Brent Crude Oil (Brent) Linked Gas Sales Contract | Significant Other Observable Inputs (Level 2)
Financial Assets:
Assets, fair value disclosure	0
Brent Crude Oil (Brent) Linked Gas Sales Contract | Significant Unobservable Inputs (Level 3)
Financial Assets:
Assets, fair value disclosure	65
Brent Linked Gas Sales Contract
Financial Assets:
Assets, fair value disclosure		110
Brent Linked Gas Sales Contract | Quoted Prices in Active Markets (Level 1)
Financial Assets:
Assets, fair value disclosure		0
Brent Linked Gas Sales Contract | Significant Other Observable Inputs (Level 2)
Financial Assets:
Assets, fair value disclosure		0
Brent Linked Gas Sales Contract | Significant Unobservable Inputs (Level 3)
Financial Assets:
Assets, fair value disclosure		$ 110
Natural Gas Liquids | Price Swaps
Financial Assets:
Assets, fair value disclosure	1
Financial Liabilities:
Liabilities, fair value disclosure	1
Natural Gas Liquids | Price Swaps | Quoted Prices in Active Markets (Level 1)
Financial Assets:
Assets, fair value disclosure	0
Financial Liabilities:
Liabilities, fair value disclosure	0
Natural Gas Liquids | Price Swaps | Significant Other Observable Inputs (Level 2)
Financial Assets:
Assets, fair value disclosure	1
Financial Liabilities:
Liabilities, fair value disclosure	1
Natural Gas Liquids | Price Swaps | Significant Unobservable Inputs (Level 3)
Financial Assets:
Assets, fair value disclosure	0
Financial Liabilities:
Liabilities, fair value disclosure	$ 0