Commitments and Guarantees - Schedule Of Repurchase Agreements (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Fair value of indemnified securities financing	$ 387,314	$ 342,337
Fair value of cash and securities held by us, as agent, as collateral for indemnified securities financing	405,299	357,893
Fair value of collateral for indemnified securities financing invested in indemnified repurchase agreements	47,560	42,610
Fair value of cash and securities held by us or our agents as collateral for investments in indemnified repurchase agreements	$ 50,351	$ 45,064