Debt and Credit Agreements - Narrative (Details)	3 Months Ended					12 Months Ended
	Mar. 31, 2025 USD ($) swap	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	[1]	Mar. 31, 2022 swap	Dec. 31, 2023 swap	Mar. 10, 2025 USD ($)	Dec. 31, 2024 USD ($)
Line of Credit Facility
Other Operating Activities	$ (4,000,000)		$ (17,000,000)
Commercial Paper
Line of Credit Facility
Maximum borrowing capacity of credit facility	1,000,000,000.0
Borrowings outstanding	$ 0
Two Separate Fixed-to-Floating Interest Rate Swaps Due 2055 | Fair Value Hedging
Line of Credit Facility
Derivative, number of fair value hedges | swap	2
Derivative, term of contract (in years)	10 years
Two Separate Fixed-to-Floating Interest Rate Swaps Due 2055 | Fair Value Hedging | Designated as Hedging Instrument
Line of Credit Facility
Interest rate fair value hedge asset at fair value	$ 8,000,000
2023 Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging | Designated as Hedging Instrument
Line of Credit Facility
Interest rate fair value hedge asset at fair value	12,000,000							$ 7,000,000
Two Separate Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging
Line of Credit Facility
Derivative, number of fair value hedges | swap						2
Five Separate Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging
Line of Credit Facility
Derivative, number of fair value hedges | swap					5
Five Separate Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging | Designated as Hedging Instrument
Line of Credit Facility
Fair value hedge derivative instrument liabilities at fair value	110,000,000							123,000,000
Interest Rate Swap | Cash Flow Hedge | Designated as Hedging Instrument
Line of Credit Facility
Asset value of the forward interest rate swap	500,000,000
Derivative asset, notional amount settled		$ 114,000,000
Other Operating Activities		$ 52,000,000
Derivative asset, unsettled notional amount	$ 0
Seven Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging
Line of Credit Facility
Derivative, number of fair value hedges | swap	7
Derivative, term of contract (in years)	10 years
Seven Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging | Designated as Hedging Instrument
Line of Credit Facility
Interest rate fair value hedge asset at fair value	$ 20,000,000							7,000,000
Fair value hedge derivative instrument liabilities at fair value	110,000,000							$ 123,000,000
5.05% Notes Due 2035
Line of Credit Facility
Debt issued							$ 600,000,000
Debt interest rate							5.05%
3.25% Notes Due 2027
Line of Credit Facility
Debt issued	$ 850,000,000
Debt interest rate	3.25%
Unsecured Revolving Credit Facility Due 2028 | Credit Facility
Line of Credit Facility
Maximum borrowing capacity of credit facility	$ 1,200,000,000
Borrowings outstanding	0
Two Separate Fixed-to-Floating Interest Rate Swaps Due 2055
Line of Credit Facility
Debt issued	250,000,000
Seven Fixed-to-Floating Interest Rate Swaps
Line of Credit Facility
Debt issued	$ 1,100,000,000

[1] See the 2024 annual report filed on Form 10-K for revision of prior period financial statements.