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Securities - Summary of Amortized Cost and Fair Values of Securities Available-for-sale (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
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Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | $ 1,183,404 | $ 834,254
Available-for-sale Securities, Gross Unrealized Gains | 7,593 | 3,130
Available-for-sale Securities, Gross Unrealized Losses | (4,705) | (19,728)
Available-for-sale Securities, Fair Value | 1,186,292 | 817,656
U.S. Treasury Notes |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 41,403 | 52,775
Available-for-sale Securities, Gross Unrealized Gains | 427 | 81
Available-for-sale Securities, Gross Unrealized Losses |  | (189)
Available-for-sale Securities, Fair Value | 41,830 | 52,667
U.S. Government Agencies |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 165,162 | 187,427
Available-for-sale Securities, Gross Unrealized Gains | 542 | 367
Available-for-sale Securities, Gross Unrealized Losses | (754) | (1,296)
Available-for-sale Securities, Fair Value | 164,950 | 186,498
Obligations of States, Municipalities, and Political Subdivisions |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 92,806 | 60,686
Available-for-sale Securities, Gross Unrealized Gains | 2,075 | 133
Available-for-sale Securities, Gross Unrealized Losses | (49) | (586)
Available-for-sale Securities, Fair Value | 94,832 | 60,233
Agency, Residential Mortgage-Backed Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 490,427 | 284,038
Available-for-sale Securities, Gross Unrealized Gains | 2,163 | 101
Available-for-sale Securities, Gross Unrealized Losses | (2,354) | (11,176)
Available-for-sale Securities, Fair Value | 490,236 | 272,963
Non-Agency, Residential Mortgage-Backed Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 109,501 | 84,998
Available-for-sale Securities, Gross Unrealized Gains | 593 | 199
Available-for-sale Securities, Gross Unrealized Losses | (272) | (1,576)
Available-for-sale Securities, Fair Value | 109,822 | 83,621
Agency, Commercial Mortgage-Backed Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 159,650 | 93,543
Available-for-sale Securities, Gross Unrealized Gains | 1,092 | 55
Available-for-sale Securities, Gross Unrealized Losses | (1,041) | (3,164)
Available-for-sale Securities, Fair Value | 159,701 | 90,434
Non-Agency, Commercial Mortgage-Backed Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 31,144 | 31,458
Available-for-sale Securities, Gross Unrealized Gains | 130 |
Available-for-sale Securities, Gross Unrealized Losses |  | (1,000)
Available-for-sale Securities, Fair Value | 31,274 | 30,458
Corporate Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 48,796 | 34,716
Available-for-sale Securities, Gross Unrealized Gains | 571 | 67
Available-for-sale Securities, Gross Unrealized Losses | (37) | (610)
Available-for-sale Securities, Fair Value | 49,330 | 34,173
Asset-Backed Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost | 44,515 |
Available-for-sale Securities, Gross Unrealized Losses | (198) |
Available-for-sale Securities, Fair Value | $ 44,317 |
Other Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available-for-sale Securities, Amortized Cost |  | 4,613
Available-for-sale Securities, Gross Unrealized Gains |  | 2,127
Available-for-sale Securities, Gross Unrealized Losses |  | (131)
Available-for-sale Securities, Fair Value |  | $ 6,609

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- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
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