Loans (Narratives) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Loans And Leases Receivable Disclosure [Line Items]
Commitment to lend additional funds	$ 2,100	$ 7,700
Loan deferral amount, pandemic related	46,500	95,700
Loans	6,410,863	6,662,133
Mortgage loans in process of foreclosure amount	24,600
Non-PCD [Member]
Loans And Leases Receivable Disclosure [Line Items]
Loans	4,883,676	4,890,114
Performing Financing Receivable [Member]
Loans And Leases Receivable Disclosure [Line Items]
Recored Investment	122,500	113,900
Mortgage Loans - GNMA Buy-Back Option Program [Member]
Loans And Leases Receivable Disclosure [Line Items]
Delinquent loans	19,900	56,200
Commercial Portfolio Segment [Member]
Loans And Leases Receivable Disclosure [Line Items]
Loans	2,331,056	2,402,010
Commercial Portfolio Segment [Member] \| Non-PCD [Member]
Loans And Leases Receivable Disclosure [Line Items]
Balance of revolving loans converted to term loans, amount	17,800	21,000
Loans	2,091,502	2,118,850
Commercial Portfolio Segment [Member] \| Puerto Rico [Member] \| Government [Member]
Loans And Leases Receivable Disclosure [Line Items]
Loans	87,100	99,100
Commercial Portfolio Segment [Member] \| Property Tax Revenue [Member] \| Puerto Rico [Member] \| Government [Member]
Loans And Leases Receivable Disclosure [Line Items]
Loans	$ 86,000	$ 98,000

Loan Deferral Amount, Pandemic Related

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- Definition

Revolving Loans Converted To Term Loans Amount

+ References

No definition available.

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- Definition

This is the principal amount of loans (across all types of loans) that are overdue in payment by a set number of days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
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- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
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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.

+ References

No definition available.

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18794-111554

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- Definition

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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