Commitments and Contingencies - Summary (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Investments in affordable housing projects
Other Commitments [Line Items]
Carrying amount	$ 2,152	$ 2,088
Amount of future funding commitments included in carrying amount	949	919
Lending exposure	455	460
Tax credits subject to recapture	489	523
Private equity investments
Other Commitments [Line Items]
Carrying amount	460	458
Amount of future funding commitments not included in carrying amount	$ 313	$ 331

Lending commitments to Affordable Housing Projects

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- Definition

Tax Credits Subject To Recapture Related To Affordable Housing Projects

+ References

No definition available.

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- Definition

Amount of investment in qualified affordable housing projects.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=114775393&loc=SL49122993-202985

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- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

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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.

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- Definition

Amount of commitment or contingent commitments to qualified affordable housing project investments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=114775393&loc=SL49122993-202985

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- Definition

Aggregate carrying value of owned private equity or other securities for which a quoted market price is not readily determinable, the value of which has been determined by management based upon fair value methods, including pricing of similar securities and valuation techniques and is included in the schedule of financial condition or the balance sheet.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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