Loans and Leases - Narrative (Details) $ in Billions	3 Months Ended	12 Months Ended
Mar. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan
Financing Receivable, Recorded Investment [Line Items]
Loans and leases pledged as collateral \| $	$ 2.1	$ 1.5
Loans modified in troubled debt restructurings	0	0
Loans more than 90 days past due	0	0
Commercial and Financial
Financing Receivable, Recorded Investment [Line Items]
Number of loans on non-accrual status	1	1
Commercial Real Estate
Financing Receivable, Recorded Investment [Line Items]
Number of loans on non-accrual status	0	0

Financing Receivable Recorded Investment Equal To Greater Than 90 Day

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- Definition

Financing Receivable, Recorded Investment, Nonaccrual Status, Number of Loans

+ References

No definition available.

+ Details

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

+ 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

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5086-111524

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- Details

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- Details

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