Pledged assets and collateral (Details) - USD ($) $ in Billions	Sep. 30, 2015	Dec. 31, 2014
Pledged assets and Collateral
Financial instruments pledged by the Firm that may not be sold or repledged by the secured parties	$ 51.8	$ 60.1
Fair value of financial assets accepted as collateral to sell or repledge, deliver or otherwise use	781.8	761.7
Collateral received that was sold or repledged	636.7	596.8
Assets pledged to Federal Reserve Banks and Federal Home Loan Banks
Pledged assets and Collateral
Pledged assets	$ 364.7	$ 324.5