v3.26.1
Fair Value Measurements
 6 Months Ended
Jun. 30, 2026
Fair Value Disclosures [Abstract]  
Fair Value Measurements Fair Value Measurements
The following table presents financial assets and liabilities measured at fair value on a recurring basis and indicates their levels within the fair value hierarchy:

June 30, 2026December 31, 2025
Level 1Level 2
Level 3
TotalLevel 1Level 2
Level 3
Total
Assets
Money market funds(a)
$246 $— $— $246 $340 $— $— $340 
Interest rate swaps(b)
— 302 — 302 — 245 — 245 
Natural gas supply contracts(b)
— 1 90 91 — 1 50 51 
Total$246 $303 $90 $639 $340 $246 $50 $636 
Liabilities
Interest rate swaps(c)
$— $43 $— $43 $— $102 $— $102 
Natural gas supply contracts(c)
— 3 192 195 — 20 149 169 
Total$— $46 $192 $238 $— $122 $149 $271 
_______________
(a)Included in cash and cash equivalents on the condensed consolidated balance sheets.
(b)Included in derivative assets and noncurrent derivative assets on the condensed consolidated balance sheets.
(c)Included in accrued and other liabilities and other noncurrent liabilities on the condensed consolidated balance sheets.

Interest rate swaps

The fair values of the Company's interest rate swaps are classified as Level 2 and determined using a discounted cash flow method that incorporates observable inputs. The fair value calculation includes a credit valuation adjustment and forward interest rate curves for the same periods of the future maturity dates of the interest rate swaps. For further discussion, see Note 9 – Derivatives.

Level 3 unobservable inputs

The Company measures the fair value of its natural gas supply contracts using income- or options-based valuation models that incorporate present value techniques, risk free interest rates, observable forward commodity price curves, and certain other significant unobservable inputs when applicable. Unobservable inputs may include implied forward curves for illiquid delivery locations and, when applicable, volatility assumptions derived from observed historical market data and adjusted for current market conditions, as well as counterparty credit risk adjustments.

Due to the uncertainty surrounding these inputs, certain natural gas supply contracts are classified as Level 3 in the fair value hierarchy. Changes in these assumptions could materially affect the estimated fair value of the contracts. See Note 9 – Derivatives for further discussion.
The following table includes quantitative information for the unobservable inputs for Level 3 natural gas supply contracts as of June 30, 2026 (natural gas price amounts in dollars):

Valuation approachSignificant unobservable inputRange of significant unobservable inputArithmetic average of significant unobservable input
Discounted cash flow
Forward natural gas price per MMBtu(a)
$2.07 to $5.37
$3.47 
Option pricing modelVolatility
19.2% to 66.3%
28.2 %
____________
(a)    At illiquid delivery locations.

The following table provides a reconciliation of changes in the net fair value of derivative instruments measured at fair value on a recurring basis using Level 3 inputs:

Three months ended
June 30,
20262025
Beginning balance as of April 1
$(75)$(28)
Total realized and unrealized loss included in earnings(65)(131)
Settlements38 57 
Ending balance as of June 30
$(102)$(102)
Unrealized loss included in earnings $(27)$(74)
Six months ended
June 30,
20262025
Beginning balance as of January 1$(99)$6 
Total realized and unrealized loss included in earnings(92)(141)
Settlements100 33 
Transfer into Level 3(11)— 
Ending balance as of June 30$(102)$(102)
Unrealized gain (loss) included in earnings $8 $(108)

Other financial instruments

The following table presents the carrying value, fair value and fair value hierarchy of outstanding debt instruments in the condensed consolidated balance sheets:

June 30, 2026
Carrying value
Fair value
Level 1Level 2
Level 3
Total
Fixed rate debt$26,084 $23,827 $84 $— $23,911 
Variable rate debt
16,302 — 16,302 — 16,302 
December 31, 2025
Carrying value
Fair value
Level 1Level 2Level 3Total
Fixed rate debt
$25,334 $25,426 $84 $— $25,510 
Variable rate debt
9,478 1,078 8,403 — 9,481