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Investments - Gross Unrealized Losses and Fair Value for Mortgage-Backed in Unrealized Loss Position (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Less than 12 months |  |
Gross Unrealized Losses | $ (485) | $ (239)
Estimated Fair Value | 76,452 | 40,601
12 months or more |  |
Gross Unrealized Losses | 0 | (523)
Estimated Fair Value | 0 | 53,545
Gross Unrealized Losses | (485) | (762)
Estimated Fair Value | 76,452 | 94,146
Mortgage-backed securities |  |
Less than 12 months |  |
Gross Unrealized Losses | (134) | (218)
Estimated Fair Value | 46,011 | 25,624
12 months or more |  |
Gross Unrealized Losses | 0 | (440)
Estimated Fair Value | 0 | 42,448
Gross Unrealized Losses | (134) | (658)
Estimated Fair Value | 46,011 | 68,072
Utah Housing Corporation bonds |  |
Less than 12 months |  |
Gross Unrealized Losses | 0 | 0
Estimated Fair Value | 0 | 0
12 months or more |  |
Gross Unrealized Losses | 0 | (83)
Estimated Fair Value | 0 | 11,097
Gross Unrealized Losses | 0 | (83)
Estimated Fair Value | 0 | 11,097
U.S. government-sponsored enterprises and Treasuries |  |
Less than 12 months |  |
Gross Unrealized Losses | 0 | (21)
Estimated Fair Value | 0 | 14,977
12 months or more |  |
Gross Unrealized Losses | 0 | 0
Estimated Fair Value | 0 | 0
Gross Unrealized Losses | 0 | (21)
Estimated Fair Value | 0 | $ 14,977
Other securities |  |
Less than 12 months |  |
Gross Unrealized Losses | (351) |
Estimated Fair Value | 30,441 |
12 months or more |  |
Gross Unrealized Losses | 0 |
Estimated Fair Value | 0 |
Gross Unrealized Losses | (351) |
Estimated Fair Value | $ 30,441 |

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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922890-210455 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
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