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Commitments and contingent liabilities (Details) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
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Commitments to Extend Credit [Member] |  |
Other Commitments [Line Items] |  |
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability | $ 2,590,000 | $ 2,620,000
Standby Letters of Credit [Member] |  |
Other Commitments [Line Items] |  |
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability | 35,100 | 28,300
Commercial Letter of Credit and other off-balance sheet liabilities [Member] |  |
Other Commitments [Line Items] |  |
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability | $ 286 | $ 0

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- Definition The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611 + 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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