v3.25.2
Fair value measurements - Financial assets and liabilities (Detail) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities $ 15,084 $ 15,364
Investments in equity securities 267,923 271,588
Insurance and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 15,084 15,364
Investments in equity securities 267,923 271,588
The Kraft Heinz Company [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity method investments, fair value 8,408 9,994
U.S. Treasury, U.S. government corporations and agencies [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 3,857 4,459
Foreign governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 9,736 9,362
Corporate and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 1,491 1,543
Fair Value, Measurements, Recurring [Member] | Quoted Prices (Level 1) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 258,484 261,910
Derivative contract assets [1] $ 29 $ 33
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Other
Derivative contract liabilities [1] $ 11 $ 15
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Accounts payable, accruals and other liabilities Accounts payable, accruals and other liabilities
Fair Value, Measurements, Recurring [Member] | Quoted Prices (Level 1) [Member] | The Kraft Heinz Company and Occidental Petroleum Corporation [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity method investments, fair value $ 19,538 $ 23,047
Fair Value, Measurements, Recurring [Member] | Quoted Prices (Level 1) [Member] | U.S. Treasury, U.S. government corporations and agencies [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 3,823 4,425
Fair Value, Measurements, Recurring [Member] | Quoted Prices (Level 1) [Member] | Foreign governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 9,601 9,199
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 10 10
Loans and finance receivables 396 810
Derivative contract assets [1] $ 152 $ 158
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Other
Derivative contract liabilities [1] $ 105 $ 143
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Accounts payable, accruals and other liabilities Accounts payable, accruals and other liabilities
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Insurance and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings $ 40,284 $ 40,158
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Railroad, Utilities and Energy [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings 75,387 72,506
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury, U.S. government corporations and agencies [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 34 34
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 135 163
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 1,015 1,041
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 9,429 9,668
Loans and finance receivables 28,348 26,769
Derivative contract assets [1] $ 16 $ 10
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Other
Derivative contract liabilities [1] $ 102 $ 76
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Accounts payable, accruals and other liabilities Accounts payable, accruals and other liabilities
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Insurance and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings $ 35 $ 23
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 476 502
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 267,923 271,588
Loans and finance receivables 28,722 27,798
Derivative contract assets [1] $ 197 $ 201
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Other
Derivative contract liabilities [1] $ 218 $ 234
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Accounts payable, accruals and other liabilities Accounts payable, accruals and other liabilities
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Insurance and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings $ 45,040 $ 44,885
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Railroad, Utilities and Energy [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings 81,980 79,877
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | The Kraft Heinz Company and Occidental Petroleum Corporation [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity method investments, fair value 24,866 30,682
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | U.S. Treasury, U.S. government corporations and agencies [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 3,857 4,459
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Foreign governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 9,736 9,362
Fair Value, Measurements, Recurring [Member] | Carrying Value [Member] | Corporate and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 1,491 1,543
Fair Value, Measurements, Recurring [Member] | Fair Value [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in equity securities 267,923 271,588
Loans and finance receivables 28,744 27,579
Derivative contract assets [1] $ 197 $ 201
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other Other
Derivative contract liabilities [1] $ 218 $ 234
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Accounts payable, accruals and other liabilities Accounts payable, accruals and other liabilities
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Insurance and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings $ 40,319 $ 40,181
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Railroad, Utilities and Energy [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notes payable and other borrowings 75,387 72,506
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | The Kraft Heinz Company and Occidental Petroleum Corporation [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity method investments, fair value 19,538 23,047
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | U.S. Treasury, U.S. government corporations and agencies [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 3,857 4,459
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Foreign governments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities 9,736 9,362
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Corporate and Other [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments in fixed maturity securities $ 1,491 $ 1,543
[1] Assets are included in other assets, and liabilities are included in accounts payable, accruals and other liabilities.