Debt and Credit Agreements - Narrative (Details)	3 Months Ended					12 Months Ended
	Dec. 31, 2023 USD ($) swap	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($) swap	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 07, 2023 USD ($)	Jul. 28, 2022 USD ($)	Jul. 01, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Notional Value of Hedged Notes								$ 0
Other Operating Activities						$ (5,000,000)	$ (17,000,000)	$ 12,000,000
Quality Carriers, Inc.
Debt Instrument [Line Items]
Finance lease obligations and debt assumed											$ 68,000,000
Interest Rate Swap | Cash Flow Hedging | Designated as Hedging Instrument
Debt Instrument [Line Items]
Interest rate fair value hedge asset at fair value	$ 48,000,000			$ 127,000,000		48,000,000	127,000,000
Derivative asset, notional value	114,000,000			340,000,000		114,000,000	340,000,000					$ 500,000,000
Cash flow hedge derivative instrument assets at fair value	$ 48,000,000			127,000,000		48,000,000	127,000,000
Notional amount settled		$ 113,000,000	$ 113,000,000	160,000,000
Derivative, cash received on hedge				52,000,000
Other Operating Activities		$ 51,000,000	$ 44,000,000
2023 Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging
Debt Instrument [Line Items]
Derivative, number of fair value hedges | swap	2
Derivative, term of contract	10 years
2023 Fixed-to-Floating Interest Rate Swaps | Fair Value Hedging | Designated as Hedging Instrument
Debt Instrument [Line Items]
Interest rate fair value hedge asset at fair value	$ 19,000,000					19,000,000
2022 Fixed-to-Floating Interest Rate Swap | Fair Value Hedging
Debt Instrument [Line Items]
Derivative, number of fair value hedges | swap					5
Derivative, term of contract					10 years
2022 Fixed-to-Floating Interest Rate Swap | Fair Value Hedging | Designated as Hedging Instrument
Debt Instrument [Line Items]
Interest rate fair value hedge liability at fair value	107,000,000			118,000,000		107,000,000	118,000,000
Commercial Paper
Debt Instrument [Line Items]
Line of credit facility capacity	1,000,000,000					1,000,000,000
Line of credit amount outstanding	0					0
3.25% Notes Due 2027
Debt Instrument [Line Items]
Notional Value of Hedged Notes	$ 850,000,000					$ 850,000,000
Interest rate	3.25%					3.25%
Unsecured Revolving Credit Facility Expiring March 2024 | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility capacity				1,200,000,000			1,200,000,000
Line of credit facility, amount outstanding	$ 0					$ 0
4.1% Notes Due 2032
Debt Instrument [Line Items]
Notional Value of Hedged Notes										$ 950,000,000
Interest rate										4.10%
4.5% Notes Due 2052
Debt Instrument [Line Items]
Notional Value of Hedged Notes										$ 900,000,000
Interest rate										4.50%
4.65% Notes Due 2068
Debt Instrument [Line Items]
Notional Value of Hedged Notes										$ 150,000,000
Interest rate										4.65%
Fixed Rate Notes Due Between 2036 and 2040
Debt Instrument [Line Items]
Notional Value of Hedged Notes	1,050,000,000			$ 800,000,000	$ 800,000,000	1,050,000,000	$ 800,000,000
Fixed Rate Notes Due 2033
Debt Instrument [Line Items]
Notional Value of Hedged Notes	250,000,000					250,000,000
5.2% Notes Due 2033
Debt Instrument [Line Items]
Notional Value of Hedged Notes									$ 600,000,000
Interest rate									5.20%
Unsecured Revolving Credit Facility Due 2028 | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility capacity	$ 1,200,000,000					$ 1,200,000,000