v3.20.4
Unsecured Borrowings - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Debt Instrument [Line Items]      
Subordinated debt maturities, range, end Dec. 31, 2065    
Minimum redemption or purchase price required $ 253.0    
Debt Instrument, Maturity Date Range, End Dec. 31, 2065    
Unsecured long-term borrowings for which the firm did not elect the fair value option $ 172,570.0 $ 163,420.0  
Fair value of unsecured long-term borrowings $ 183,290.0 $ 168,600.0  
Subordinated Debt [Member]      
Debt Instrument [Line Items]      
Subordinated debt maturities, range, start Dec. 31, 2025 Dec. 31, 2021  
Subordinated debt maturities, range, end Dec. 31, 2045 Dec. 31, 2045  
Trust Preferred Securities purchased, par amount $ 8.1 $ 164.0 $ 29.0
Trust Preferred Securities purchased, carrying value $ 12.5 $ 231.0 36.0
Debt Instrument, Maturity Date Range, End Dec. 31, 2045 Dec. 31, 2045  
Goldman Sachs Capital I [Member]      
Debt Instrument [Line Items]      
Junior subordinated debentures issued to Goldman Sachs Capital I (Trust) $ 2,840.0    
Guaranteed preferred beneficial interests issued to third parties 2,750.0    
Common beneficial interests issued to Group Inc. 85.0    
Junior subordinated debt, outstanding par amount 968.0 $ 976.0  
Trust Preferred Securities, outstanding par amount 939.0 947.0  
Common beneficial interests, outstanding par amount 29.0 29.0  
Trust Preferred Securities purchased, par amount 7.9 159.0 28.0
Trust Preferred Securities purchased, carrying value 11.0 206.0 35.0
Common beneficial interests delivered to the Trust $ 0.2 $ 5.0 $ 1.0
Interest Rate of Junior Subordinated Debentures held by certain third parties 6.345%    
Maturity date of Junior Subordinated Debentures held by certain third parties Feb. 15, 2034    
Interest Rate of Junior Subordinated Debentures issued to Trust, Fixed 6.345%    
Maturity date of Junior Subordinated Debentures issued to Trust Feb. 15, 2034