Commitments, Contingencies and Guarantees - Schedule of Commitments, Contingencies and Guarantees (Details) $ in Millions	Sep. 30, 2019 USD ($)
Commitments to extend credit
Commitment, Contingencies and Guarantees disclosures
Commitments	$ 37,999
Issued standby and commercial letters of credit
Commitment, Contingencies and Guarantees disclosures
Commitments	4,348
Commitments to enter into forward-starting resale agreements
Commitment, Contingencies and Guarantees disclosures
Commitments	1,441
Other commitments
Commitment, Contingencies and Guarantees disclosures
Commitments	$ 483