v3.26.1
Fair Value Disclosures - Changes in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance $ 367 $ 363
Realized and Unrealized Gains (Losses),Assets (9) (10)
Purchases, Assets 28 15
Sales and Maturities, Assets (9) (30)
Issuances and other Settlements, Assets 0 0
Transfers into Level 3, Assets 0 0
Transfers out of Level 3, Assets 0 0
Assets measured at fair value, ending balance 377 338
Total Net Unrealized Gains (Losses) Included in Earnings (9) (10)
Liabilities measured at fair value, beginning balance   4,431
Realized and Unrealized Gains (Losses), Liabilities   96
Purchases, Liabilities   0
Sales and Maturities, Liabilities   0
Issuances and other Settlements, Liabilities   (35)
Transfers into Level 3, Liabilities   0
Transfers out of Level 3, Liabilities   0
Liabilities measured at fair value, ending balance   4,492
Total Net Unrealized Gains (Losses) Included in Earnings   96
Other Assets [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 151 149
Assets measured at fair value, ending balance 149 152
Other Liabilities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Liabilities measured at fair value, beginning balance   129
Liabilities measured at fair value, ending balance   102
Contingent Consideration Liabilities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Liabilities measured at fair value, beginning balance 8,429 4,302
Realized and Unrealized Gains (Losses), Liabilities $ (551) $ 99
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Business Combination, Contingent Consideration, Liability, Current Business Combination, Contingent Consideration, Liability, Current
Purchases, Liabilities $ 0 $ 0
Sales and Maturities, Liabilities 0 0
Issuances and other Settlements, Liabilities (13) (11)
Transfers into Level 3, Liabilities 0 0
Transfers out of Level 3, Liabilities 0 0
Liabilities measured at fair value, ending balance 7,865 4,390
Total Net Unrealized Gains (Losses) Included in Earnings (551) 99
Investments [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 216 214
Realized and Unrealized Gains (Losses),Assets (7) (13)
Purchases, Assets 28 15
Sales and Maturities, Assets (9) (30)
Issuances and other Settlements, Assets 0 0
Transfers into Level 3, Assets 0 0
Transfers out of Level 3, Assets 0 0
Assets measured at fair value, ending balance 228 186
Total Net Unrealized Gains (Losses) Included in Earnings (7) (13)
Debt securities [Member] | Trading [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 7 79
Realized and Unrealized Gains (Losses),Assets 0 (2)
Purchases, Assets 28 4
Sales and Maturities, Assets 0 (2)
Issuances and other Settlements, Assets 0 0
Transfers into Level 3, Assets 0 0
Transfers out of Level 3, Assets 0 0
Assets measured at fair value, ending balance 35 79
Total Net Unrealized Gains (Losses) Included in Earnings $ 0 $ (2)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Nonoperating Income (Expense) Nonoperating Income (Expense)
Mutual Funds [Member] | Equity Securities Mutual Funds [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance $ 136  
Realized and Unrealized Gains (Losses),Assets  
Purchases, Assets 0  
Sales and Maturities, Assets 0  
Issuances and other Settlements, Assets 0  
Transfers into Level 3, Assets 0  
Transfers out of Level 3, Assets 0  
Assets measured at fair value, ending balance 136  
Total Net Unrealized Gains (Losses) Included in Earnings 0  
Loans [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 73  
Realized and Unrealized Gains (Losses),Assets (7)  
Purchases, Assets 0  
Sales and Maturities, Assets (9)  
Issuances and other Settlements, Assets 0  
Transfers into Level 3, Assets 0  
Transfers out of Level 3, Assets 0  
Assets measured at fair value, ending balance 57  
Total Net Unrealized Gains (Losses) Included in Earnings (7)  
Consolidated Variable Interest Entities [Member] | Loans [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance   $ 135
Realized and Unrealized Gains (Losses),Assets   (11)
Purchases, Assets   11
Sales and Maturities, Assets   (28)
Issuances and other Settlements, Assets   0
Transfers into Level 3, Assets   0
Transfers out of Level 3, Assets   0
Assets measured at fair value, ending balance   107
Total Net Unrealized Gains (Losses) Included in Earnings   (11)
Other Assets One [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Realized and Unrealized Gains (Losses),Assets (2) 3
Purchases, Assets 0 0
Sales and Maturities, Assets 0 0
Issuances and other Settlements, Assets 0 0
Transfers into Level 3, Assets 0 0
Transfers out of Level 3, Assets 0 0
Total Net Unrealized Gains (Losses) Included in Earnings $ (2) 3
Other Liabilities One [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Realized and Unrealized Gains (Losses), Liabilities   (3)
Purchases, Liabilities   0
Sales and Maturities, Liabilities   0
Issuances and other Settlements, Liabilities   (24)
Transfers into Level 3, Liabilities   0
Transfers out of Level 3, Liabilities   0
Total Net Unrealized Gains (Losses) Included in Earnings   $ (3)
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]   Nonoperating Income (Expense)