Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Schedule of cash and cash equivalents and other investments reconciliation from adjusted cost to fair value

Our cash and cash equivalents and other investments consist of the following:

	March 31, 2026
	Cost Basis		Unrealized Gains		Unrealized Losses		Fair Value
	(in millions)
Cash	$	445	$	—	$	—	$	445
Cash equivalents:
U.S. and Canadian government obligations	277		—		—		277
Other debt securities	1,320		—		—		1,320
Total cash and cash equivalents	$	2,042	$	—	$	—	$	2,042
Nonqualified employee benefit trusts	15		3		—		18

	December 31, 2025
	Cost Basis		Unrealized Gains		Unrealized Losses		Fair Value
	(in millions)
Cash	$	629	$	—	$	—	$	629
Cash equivalents:
U.S. and Canadian government obligations	284		—		—		284
Other debt securities	1,069		—		—		1,069
Total cash and cash equivalents	$	1,982	$	—	$	—	$	1,982
Nonqualified employee benefit trusts	15		3		—		18

Schedule of assets and liabilities measured at fair value on a recurring basis

The following tables present assets and liabilities included in our consolidated balance sheets as of March 31, 2026 and December 31, 2025 that are recognized at fair value on a recurring basis, and indicate the fair value hierarchy utilized to determine such fair value:

	March 31, 2026
	Total Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in millions)
Cash equivalents	$	1,597	$	1,597	$	—	$	—
Nonqualified employee benefit trusts	18		18		—		—
Derivative assets	1		—		1		—
Derivative liabilities	(2)		—		(2)		—

	December 31, 2025
	Total Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in millions)
Cash equivalents	$	1,353	$	1,353	$	—	$	—
Nonqualified employee benefit trusts	18		18		—		—
Derivative assets	1		—		1		—
Derivative liabilities	(5)		—		(5)		—

Schedule of carrying amounts and estimated fair values of financial instruments

The carrying amount and estimated fair value of our financial instruments are as follows:

	March 31, 2026				December 31, 2025
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Long-term debt	$	3,216	$	3,109	$	3,215	$	3,131