Commitments, Pledged Assets, and Collateral - Pledged Assets and Collateral (Details) - USD ($) $ in Billions	Dec. 31, 2016	Dec. 31, 2015
Significant components of assets pledged
Significant components of assets pledged as collateral, fair value	$ 629.0	$ 567.8
Financial instruments pledged by the Firm that may not be sold or repledged by the secured parties	53.5	50.7
Collateral Received that Can be Resold or Repledged
Assets accepted by the Firm as collateral that it could sell or repledge, deliver or otherwise use at fair value	914.1	748.5
Assets accepted by the Firm as collateral that the Firm has sold or repledged	746.6	580.9
Securities
Significant components of assets pledged
Significant components of assets pledged as collateral, fair value	101.1	124.3
Loans
Significant components of assets pledged
Significant components of assets pledged as collateral, fair value	374.9	298.6
Trading assets and other
Significant components of assets pledged
Significant components of assets pledged as collateral, fair value	153.0	144.9
Assets pledged to Federal Reserve Banks and Federal Home Loan Banks
Significant components of assets pledged
Significant components of assets pledged as collateral, fair value	$ 441.9	$ 385.6