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Investment Securities Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands | Jun. 30, 2021 | Dec. 31, 2020
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Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | $ 554,225 | $ 361,844
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 5,499 | 8,017
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (3,904) | (10)
Securities held to maturity, fair value | 555,820 | 369,851
US Government Agencies Residential Mortgage-backed Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 2,652 | 2,766
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 128 | 138
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | 2,780 | 2,904
US Government Agency Debt Securities Commercial [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 102,982 | 36,799
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 818 | 1,441
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (728) | 0
Securities held to maturity, fair value | 103,072 | 38,240
Residential Mortgage Backed Securities [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 384,392 | 277,351
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 3,712 | 5,389
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (2,645) | (10)
Securities held to maturity, fair value | 385,459 | 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 | 8,527 | 9,737
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 275 | 344
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | 0 | 0
Securities held to maturity, fair value | 8,802 | 10,081
Obligations of States and Political Subdivisions [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 32,925 | 34,391
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain | 566 | 705
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss | (79) | 0
Securities held to maturity, fair value | 33,412 | 35,096
Debt Security, Government, Non-US [Member] |  |
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities, Held-to-maturity | 1,000 | 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 | $ 1,000 | $ 800

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- Definition Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524 Reference 4: 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=123581744&loc=d3e27232-111563 + Details
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