v3.20.4
Fair Value Measurements - Financial Assets Liabilities Summary (Detail) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total financial assets at fair value $ 627,073 $ 539,568
Total assets $ 1,163,028 $ 992,968
Total level 3 financial assets divided by total assets 2.30% 2.30%
Total level 3 financial assets divided by total financial assets at fair value 4.20% 4.30%
Total financial liabilities at fair value $ 389,577 $ 332,959
Total liabilities $ 1,067,096 $ 902,703
Total level 3 financial liabilities divided by total liabilities 3.10% 2.90%
Total level 3 financial liabilities divided by total financial liabilities at fair value 8.50% 7.80%
Counterparty and Cash Collateral Netting [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total financial assets at fair value $ (77,170) $ (55,527)
Total financial liabilities at fair value (60,297) (41,671)
Investments in funds at NAV [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total financial assets at fair value 3,664 4,206
Level 1 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total financial assets at fair value 263,999 242,562
Total financial liabilities at fair value 85,120 54,790
Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total financial assets at fair value 410,275 325,259
Total financial liabilities at fair value 331,824 293,902
Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total financial assets at fair value 26,305 23,068
Total financial liabilities at fair value $ 32,930 $ 25,938