Commitments and contingent liabilities - Significant Industry Concentrations Related to Credit Exposure (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	$ 54,953	$ 56,564
Financial institutions
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	12,500
Unfunded commitments	34,400
Total exposure	46,900
Financial institutions \| Securities industry
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	2,900
Unfunded commitments	23,400
Total exposure	26,300
Financial institutions \| Banks
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	7,400
Unfunded commitments	1,100
Total exposure	8,500
Financial institutions \| Asset managers
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	1,300
Unfunded commitments	6,400
Total exposure	7,700
Financial institutions \| Insurance
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	0
Unfunded commitments	2,700
Total exposure	2,700
Financial institutions \| Government
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	100
Unfunded commitments	300
Total exposure	400
Financial institutions \| Other
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	800
Unfunded commitments	500
Total exposure	1,300
Commercial
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	1,800
Unfunded commitments	12,600
Total exposure	14,400
Commercial \| Manufacturing
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	900
Unfunded commitments	4,200
Total exposure	5,100
Commercial \| Services and other
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	600
Unfunded commitments	3,700
Total exposure	4,300
Commercial \| Energy and utilities
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	300
Unfunded commitments	3,700
Total exposure	4,000
Commercial \| Media and telecom
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loans	0
Unfunded commitments	1,000
Total exposure	$ 1,000

The sum of loans outstanding and unfunded credit commitments

No definition available.

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- Definition

Credit commitments to extend credit to a counterparty under certain terms and conditions.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount before allowance and after 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5074-111524

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