Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Unfunded credit facilities	$ 30,971	$ 29,697
Indemnified securities financing	376,975	367,901
Standby letters of credit	$ 3,273	$ 3,324
Unfunded Commitments Set to Expire	75.00%