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Loans and Allowances for Credit Losses, Troubled Debt Restructurings (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Troubled Debt Restructuring, Recorded Investment | $ 152,000 | $ 169,000 | $ 152,000 | $ 169,000 | $ 126,000
Troubled Debt Restructuring, Performing in Accordance With Modified Terms | 80,000 | 71,000 | 80,000 | 71,000 | 48,000
Financing Receivable, Modifications, Post-Modification Recorded Investment | 19,000 | 34,000 | 32,000 | 53,000 |
Troubled Debt Restructuring, Charge-offs | 5,500 | 10 | 5,600 | 42 |
Permanent mortgages guaranteed by US government agencies [Member] | Accruing [Member] | Residential mortgage |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Troubled Debt Restructuring, Recorded Investment | $ 75,000 | $ 81,000 | $ 75,000 | $ 81,000 | $ 74,000

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- Definition Represents the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructuring and are performing according to modified terms. + References No definition available. + Details
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- Definition Post-modification amount of investment in financing receivables 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=84173941&loc=SL6953676-111524 + Details
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- Definition The amount of the outstanding recorded investment related to 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 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
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- Definition Reflects the amount of the write-down related to a troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
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