v3.26.1
Debt - Carrying Values of Debt Instruments (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Mar. 31, 2025
Debt Instrument [Line Items]      
Finance leases and other $ 443 $ 441  
Long-term debt, gross and lease obligation 14,205 13,710  
Adjustments (136) (129)  
Total Debt 14,069 13,581  
Less: current portion (548) (596)  
Long-term portion 13,521 12,985  
Credit facilities: Uncommitted Credit Facility      
Debt Instrument [Line Items]      
Principal 72 0  
Adjustments 0 0  
Carrying Value 72 0  
Credit facilities: The Credit Facility      
Debt Instrument [Line Items]      
Principal 182 425  
Adjustments 0 0  
Carrying Value 182 425  
Credit facilities: Commercial Paper Facility      
Debt Instrument [Line Items]      
Principal 420 1,000  
Adjustments 0 (1)  
Carrying Value $ 420 999  
Senior notes: July 2026      
Debt Instrument [Line Items]      
Interest Rate 2.90%    
Principal $ 500 500  
Adjustments 0 0  
Carrying Value $ 500 500  
Senior notes: November 2027      
Debt Instrument [Line Items]      
Interest Rate 3.375%    
Principal $ 650 650  
Adjustments (1) (1)  
Carrying Value $ 649 649  
Senior notes: May 2028      
Debt Instrument [Line Items]      
Interest Rate 3.95%    
Principal $ 800 800  
Adjustments (4) (5)  
Carrying Value $ 796 795  
Senior notes: April 2029      
Debt Instrument [Line Items]      
Interest Rate 4.875%    
Principal $ 750 750  
Adjustments (4) (5)  
Carrying Value $ 746 745  
Senior notes: November 2029      
Debt Instrument [Line Items]      
Interest Rate 5.00%    
Principal $ 400 400  
Adjustments (3) (3)  
Carrying Value $ 397 397  
Senior notes: March 2030      
Debt Instrument [Line Items]      
Interest Rate 2.30%    
Principal $ 600 600  
Adjustments (3) (3)  
Carrying Value $ 597 597  
Senior notes: July 2030      
Debt Instrument [Line Items]      
Interest Rate 4.75%    
Principal $ 500 500 $ 500
Adjustments (5) (5)  
Carrying Value $ 495 495  
Senior notes: February 2031      
Debt Instrument [Line Items]      
Interest Rate 1.45%    
Principal $ 650 650  
Adjustments (4) (5)  
Carrying Value $ 646 645  
Senior notes: July 2031      
Debt Instrument [Line Items]      
Interest Rate 4.75%    
Principal $ 700 0  
Adjustments (6) 0  
Carrying Value $ 694 0  
Senior notes: February 2032      
Debt Instrument [Line Items]      
Interest Rate 1.75%    
Principal $ 750 750  
Adjustments (4) (4)  
Carrying Value $ 746 746  
Senior notes: March 2033      
Debt Instrument [Line Items]      
Interest Rate 2.375%    
Principal $ 700 700  
Adjustments (5) (5)  
Carrying Value $ 695 695  
Senior notes: December 2033      
Debt Instrument [Line Items]      
Interest Rate 5.00%    
Principal $ 650 650  
Adjustments (7) (8)  
Carrying Value $ 643 642  
Senior notes: April 2034      
Debt Instrument [Line Items]      
Interest Rate 5.00%    
Principal $ 800 800  
Adjustments (9) (9)  
Carrying Value $ 791 791  
Senior notes: November 2034      
Debt Instrument [Line Items]      
Interest Rate 5.20%    
Principal $ 500 500  
Adjustments (5) (5)  
Carrying Value $ 495 495  
Senior notes: March 2035      
Debt Instrument [Line Items]      
Interest Rate 6.086%    
Principal $ 182 182  
Adjustments (9) (10)  
Carrying Value $ 173 172  
Senior notes: March 2035      
Debt Instrument [Line Items]      
Interest Rate 5.15%    
Principal $ 700 700 $ 700
Adjustments (10) (10)  
Carrying Value $ 690 690  
Senior notes: July 2036      
Debt Instrument [Line Items]      
Interest Rate 5.00%    
Principal $ 500 0  
Adjustments (9) 0  
Carrying Value $ 491 0  
Senior notes: March 2040      
Debt Instrument [Line Items]      
Interest Rate 6.20%    
Principal $ 400 400  
Adjustments (3) (3)  
Carrying Value $ 397 397  
Senior notes: May 2041      
Debt Instrument [Line Items]      
Interest Rate 5.70%    
Principal $ 386 386  
Adjustments (4) (5)  
Carrying Value $ 382 381  
Senior notes: March 2050      
Debt Instrument [Line Items]      
Interest Rate 3.05%    
Principal $ 400 400  
Adjustments (6) (7)  
Carrying Value $ 394 393  
Debentures: September 2035      
Debt Instrument [Line Items]      
Interest Rate 7.40%    
Principal $ 148 148  
Adjustments (25) (26)  
Carrying Value 123 122  
Tax-exempt      
Debt Instrument [Line Items]      
Principal 1,422 1,378  
Adjustments (10) (9)  
Carrying Value $ 1,412 $ 1,369  
Tax-exempt | Minimum      
Debt Instrument [Line Items]      
Interest Rate 2.55%    
Tax-exempt | Maximum      
Debt Instrument [Line Items]      
Interest Rate 4.375%    
Finance leases | Minimum      
Debt Instrument [Line Items]      
Interest Rate 1.726%    
Finance leases | Maximum      
Debt Instrument [Line Items]      
Interest Rate 9.75%