Loans and Leases - Net Loans (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 27,009	$ 25,789
Allowance for loan and lease losses	(71)	(67)
Loans and leases, net of allowance	26,938	25,722
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	19,028	20,353
Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	7,981	5,436
Loans to investment funds | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	13,747	15,050
Overdrafts	6,140	5,440
Loans to investment funds | Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	6,868	4,505
Senior secured bank loans | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3,145	3,490
Senior secured bank loans | Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,113	931
Loans to municipalities | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	762	902
Other | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	28	37
Commercial Real Estate | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 1,346	$ 874