Loans and Leases - Net Loans (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 23,294	$ 19,757
Allowance for loan and lease losses	(54)	(53)
Loans and leases, net of allowance	23,240	19,704
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to investment funds	13,618	11,734
Senior secured bank loans	2,923	3,256
Loans to municipalities	2,105	1,352
Other	50	70
Commercial real estate	98	27
Lease financing	267	338
Total loans and leases	19,061	16,777
Non-U.S.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to investment funds	3,213	2,224
Senior secured bank loans	624	252
Lease financing	396	504
Total loans and leases	$ 4,233	$ 2,980

Loans Receivable, Gross, Commercial, Financial Institutions, Secured

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Loans and Leases Receivable, Gross, Commercial, Other

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Amount before allowance of commercial leases and leveraged lease transactions where the entity is long-term creditor. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes leases covered under loss sharing agreements.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases issued to a unit or agency of a federal, state or local jurisdiction within the country of domicile of the reporting entity. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount before allowance of loans issued to financial institutions, including, but not limited to, real estate investment trusts, mortgage companies, and banks. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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Amount before allowance of commercial loans issued to businesses to acquire, develop, construct, improve, or refinance land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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