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Investment Securities Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
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Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | $ 407,833 | $ 361,844
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 6,049 | 8,017
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (5,764) | (10)
Securities held to maturity, fair value | 408,118 | 369,851
US Government Agencies Residential Mortgage-backed Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 2,679 | 2,766
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 123 | 138
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | 2,802 | 2,904
US Government Agency Debt Securities Commercial [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 58,484 | 36,799
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 992 | 1,441
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (512) | 0
Securities held to maturity, fair value | 58,964 | 38,240
Residential Mortgage Backed Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 279,970 | 277,351
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 4,134 | 5,389
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (3,763) | (10)
Securities held to maturity, fair value | 280,341 | 282,730
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 9,121 | 9,737
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 316 | 344
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | 9,437 | 10,081
Obligations of States and Political Subdivisions [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 35,109 | 34,391
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 484 | 705
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (264) | 0
Securities held to maturity, fair value | 35,329 | 35,096
Debt Security, Government, Non-US [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 800 | 800
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 0 | 0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | $ 800 | $ 800

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- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
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- Definition Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563 + Details
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