Commitments and Guarantees - Schedule Of Repurchase Agreements (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Fair value of indemnified securities financing	$ 379,459	$ 360,452
Fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	396,123	377,919
Fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	68,243	60,003
Fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements	$ 73,157	$ 63,959