Regulatory Requirements - The Firm's Regulatory Capital and Capital Ratios (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Required Ratio
Common Equity Tier 1 capital (as a percent)	10.00%	8.60%
Tier 1 capital (as a percent)	11.50%	10.10%
Total capital (as a percent)	13.50%	12.10%
Tier 1 leverage (as a percent)	4.00%	4.00%
SLR (as a percent)	5.00%	5.00%
Amount
Common Equity Tier 1 capital	$ 64,348	$ 62,086
Tier 1 capital	72,937	70,619
Total capital	82,661	80,052
Total RWA	394,875	367,309
Tier 1 leverage	72,937	70,619
Adjusted average assets	892,912	843,074
SLR	72,937	70,619
Supplementary leverage exposure	$ 1,155,497	$ 1,092,672
Ratio
Common Equity Tier 1 capital (as a percent)	16.30%	16.90%
Tier 1 capital (as a percent)	18.50%	19.20%
Total capital (as a percent)	20.90%	21.80%
Tier 1 leverage (as a percent)	8.20%	8.40%
SLR (as a percent)	6.30%	6.50%