v3.25.4
Schedule of Valuation and Qualifying Accounts (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period $ 5,588 $ 5,842 $ 5,720
Charged to costs and expenses (2,530) 201 531
Deductions 491 455 409
Balance at end of period 2,567 5,588 5,842
Credit losses      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period 900 899 857
Charged to costs and expenses 530 430 385
Deductions 481 429 343
Balance at end of period 949 900 899
Doubtful receivables      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period 77 69 93
Charged to costs and expenses 32 23 30
Deductions 7 15 54
Balance at end of period 102 77 69
Inventories (primarily service part obsolescence)      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period 755 687 718
Charged to costs and expenses 133 68 (31)
Deductions 0 0 0
Balance at end of period 888 755 687
Deferred tax assets      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period 407 846 822
Charged to costs and expenses 25 (428) 36
Deductions 3 11 12
Balance at end of period 429 407 846
Deferred tax assets for U.S. flow-through operations      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of period 3,449 3,341 3,230
Charged to costs and expenses (3,250) 108 111
Deductions 0 0 0
Balance at end of period $ 199 $ 3,449 $ 3,341