Debt (Schedule of long-term debt instruments) (Details) - USD ($)	1 Months Ended	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2024	Mar. 15, 2024	Feb. 28, 2024	Jan. 31, 2024	Dec. 31, 2023
Debt Instrument
Finance leases	$ 210,000,000	$ 210,000,000				$ 192,000,000
Total debt	12,405,000,000	12,405,000,000				11,518,000,000
Less short-term portion	(1,087,000,000)	(1,087,000,000)				(1,465,000,000)
Total long-term debt	11,318,000,000	11,318,000,000				10,053,000,000
Accounts Receivable Securitization Facility expiring 2024 | Line of Credit
Debt Instrument
Long-term debt	1,021,000,000	1,021,000,000				1,300,000,000
Borrowing capacity, net of letters of credit	$ 279,000,000	$ 279,000,000
Interest rate at March 31, 2024	6.30%	6.30%
Average month-end debt outstanding		$ 1,093,000,000
Weighted-average interest rate on average debt outstanding	6.30%	6.30%
Maximum month-end debt outstanding		$ 1,132,000,000
Collateral amount	$ 1,348,000,000	$ 1,348,000,000
Debt instrument, extension period		364 days
Term loan facility expiring 2031
Debt Instrument
Long-term debt	$ 990,000,000	$ 990,000,000				945,000,000
Annual repayment rate	1.00%	1.00%
Long-term debt, gross				$ 1,000,000,000	$ 948,000,000
Term loan facility | Line of Credit
Debt Instrument
Borrowing capacity, net of letters of credit	$ 0	$ 0
Interest rate at March 31, 2024	7.10%	7.10%
Average month-end debt outstanding		$ 983,000,000
Weighted-average interest rate on average debt outstanding	7.10%	7.10%
Maximum month-end debt outstanding		$ 1,000,000,000
Line of Credit | $4.25 billion ABL Facility expiring 2027
Debt Instrument
Maximum borrowing capacity	$ 4,250,000,000	4,250,000,000
Long-term debt	1,371,000,000	1,371,000,000				1,261,000,000
Borrowing capacity, net of letters of credit	2,853,000,000	2,853,000,000
Letters of credit	$ 18,000,000	$ 18,000,000
Interest rate at March 31, 2024	6.50%	6.50%
Average month-end debt outstanding		$ 1,346,000,000
Weighted-average interest rate on average debt outstanding	6.50%	6.50%
Maximum month-end debt outstanding		$ 1,457,000,000
Senior notes | 5 1/2 percent Senior Notes due 2027
Debt Instrument
Stated interest rate	5.50%	5.50%
Long-term debt	$ 498,000,000	$ 498,000,000				498,000,000
Senior notes | 3 7/8 percent Senior Secured Notes due 2027
Debt Instrument
Stated interest rate	3.875%	3.875%
Long-term debt	$ 746,000,000	$ 746,000,000				745,000,000
Senior notes | 4 7/8 percent Senior Notes due 2028
Debt Instrument
Stated interest rate	4.875%	4.875%
Long-term debt	$ 1,665,000,000	$ 1,665,000,000				1,665,000,000
Senior notes | 6 percent Senior Secured Notes due 2029
Debt Instrument
Stated interest rate	6.00%	6.00%
Long-term debt	$ 1,488,000,000	$ 1,488,000,000				1,488,000,000
Senior notes | 5 1/4 percent Senior Notes due 2030
Debt Instrument
Stated interest rate	5.25%	5.25%
Long-term debt	$ 745,000,000	$ 745,000,000				745,000,000
Senior notes | 4 percent Senior Notes due 2030
Debt Instrument
Stated interest rate	4.00%	4.00%
Long-term debt	$ 745,000,000	$ 745,000,000				744,000,000
Senior notes | 3 7/8 percent Senior Notes due 2031
Debt Instrument
Stated interest rate	3.875%	3.875%
Long-term debt	$ 1,092,000,000	$ 1,092,000,000				1,091,000,000
Senior notes | 3 3/4 percent Senior Notes due 2032
Debt Instrument
Stated interest rate	3.75%	3.75%
Long-term debt	$ 744,000,000	$ 744,000,000				744,000,000
Senior notes | 6 1/8 percent Senior Notes due 2034
Debt Instrument
Stated interest rate	6.125%	6.125%	6.125%
Long-term debt	$ 1,090,000,000	$ 1,090,000,000				0
Debt instrument, face amount			$ 1,100,000,000
Senior notes | 6 1/8 percent Senior Notes due 2034 | Subsidiaries
Debt Instrument
Debt instrument, face amount	$ 1,100,000,000	1,100,000,000
Senior notes | 6 1/8 percent Senior Notes due 2034 | Redemption Period One | Subsidiaries
Debt Instrument
Debt instrument, redemption price, percentage	103.063%
Senior notes | 6 1/8 percent Senior Notes due 2034 | Redemption Period Two | Subsidiaries
Debt Instrument
Debt instrument, redemption price, percentage	100.00%
Senior notes | 6 1/8 percent Senior Notes due 2034 | Redemption Period Three | Subsidiaries
Debt Instrument
Debt instrument, redemption price, percentage	106.125%
Senior notes | 6 1/8 percent Senior Notes due 2034 | Redemption Period Four | Subsidiaries
Debt Instrument
Debt instrument, redemption price, percentage	40.00%
Senior notes | 6 1/8 percent Senior Notes due 2034 | Redemption Period Five | Subsidiaries
Debt Instrument
Debt instrument, redemption price, percentage	101.00%
Senior notes | 4 7/8 percent Senior Notes due 2028, one
Debt Instrument
Long-term debt	$ 1,661,000,000	1,661,000,000
Senior notes | 4 7/8 percent Senior Notes due 2028, two
Debt Instrument
Long-term debt	4,000,000	4,000,000
Repurchase facility | Repurchase facility expiring 2023
Debt Instrument
Long-term debt	$ 0	$ 0				$ 100,000,000