Regulation and Capital Adequacy - Leverage Ratios (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital	$ 88,566	$ 85,440
Average total assets	1,140,901	983,909
Deductions from Tier 1 capital	(5,087)	(5,275)
Average adjusted total assets	1,135,814	978,634
Impact of SLR temporary amendment	(198,954)
Average off-balance-sheet exposures	365,008	396,833
Total leverage exposure	$ 1,301,868	$ 1,375,467
Tier 1 leverage ratio	7.80%	8.70%
SLR	0.068	0.062
GS Bank USA [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 capital	$ 30,441	$ 29,176
Average adjusted total assets	288,159	220,974
Total leverage exposure	$ 342,230	$ 413,852
Tier 1 leverage ratio	10.60%	13.20%
SLR	0.089	0.070