Loans (Narrative) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) contract	Mar. 31, 2020 contract	Dec. 31, 2020 USD ($)
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Interest Receivable, loans	$ 52,667		$ 54,831
Financing Receivable Modifications Additional Commitment To Lend	$ 672		651
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| contract	0	0
Loan modifications, short-term deferments not classified as TDR, Number of contracts \| contract	20
Loan modifications, short-term deferments not classified as TDR, net of unearned income	$ 71,400
Paycheck Protection Program (PPP) loans, net of unearned income	894,100
Loans Receivable [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	3,490,000		3,460,000
Commercial Loan [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Loans pledged to collateralize Federal Reserve Bank Borrowings	200,100		200,400
Loans [Member]
Financing Receivable, Credit Quality Indicator - interest written off on nonaccrual loans [Line Items]
Interest Receivable, loans	$ 35,200		$ 37,800

Financing Receivable Modifications Additional Commitment To Lend

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Loan modifications, short-term deferments not classified as TDR, net of unearned income

+ References

No definition available.

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Loan modifications, short-term deferments not classified as TDR, Number of contracts

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Loans pledged to collateralize Federal Reserve Bank Borrowings

+ References

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Paycheck Protection Program (PPP) loans, net of unearned income

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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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.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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