v3.19.3.a.u2
Fair Value Disclosures - Changes in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance $ 156 $ 116
Realized and Unrealized Gains (Losses),Assets   (20)
Purchases, Assets 117 35
Sales and Maturities, Assets   (14)
Issuances and Other Settlements, Assets   70
Transfers out of Level 3, Assets (79) (31)
Assets measured at fair value, ending balance 194 156
Total Net Unrealized Gains (Losses) Included in Earnings   (20)
Liabilities measured at fair value, beginning balance 371 236
Realized and Unrealized Gains (Losses), Liabilities (53) (65)
Issuances and Other Settlements, Liabilities (36) 70
Liabilities measured at fair value, ending balance 388 371
Total Net Unrealized Gains (Losses) Included in Earnings (53) (65)
Other Liabilities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Liabilities measured at fair value, beginning balance 371 236
Realized and Unrealized Gains (Losses), Liabilities (53) (65)
Issuances and Other Settlements, Liabilities (36) 70
Liabilities measured at fair value, ending balance 388 371
Total Net Unrealized Gains (Losses) Included in Earnings (53) (65)
Investments [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 156 116
Realized and Unrealized Gains (Losses),Assets   (20)
Purchases, Assets 117 35
Sales and Maturities, Assets   (14)
Issuances and Other Settlements, Assets   70
Transfers out of Level 3, Assets (79) (31)
Assets measured at fair value, ending balance 194 156
Total Net Unrealized Gains (Losses) Included in Earnings   (20)
Debt securities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 4  
Purchases, Assets 10 35
Transfers out of Level 3, Assets (6) (31)
Assets measured at fair value, ending balance 8 4
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 4  
Purchases, Assets 10 9
Transfers out of Level 3, Assets (6) (5)
Assets measured at fair value, ending balance 8 4
Consolidated Variable Interest Entities [Member] | Bank Loans [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 70  
Purchases, Assets 107  
Issuances and Other Settlements, Assets   70
Assets measured at fair value, ending balance 177 70
Consolidated Variable Interest Entities [Member] | Private/ Public Equity [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets measured at fair value, beginning balance 82 116
Realized and Unrealized Gains (Losses),Assets   (20)
Sales and Maturities, Assets   (14)
Transfers out of Level 3, Assets (73)  
Assets measured at fair value, ending balance $ 9 82
Total Net Unrealized Gains (Losses) Included in Earnings   $ (20)