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Investment Securities (Details) - USD ($) | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Held-to-maturity securities |  |
Amortized cost | $ 2,400,000 | $ 1,200,000
Estimated fair value | 2,400,000 | 1,200,000
Carrying Value | 2,400,000 | 1,200,000
Available-for-sale securities |  |
Amortized cost, Available-for-sale securities | 3,376,070,000 | 3,481,165,000
Gross Unrealized Gains | 19,467,000 |
Gross Unrealized Losses | (16,614,000) |
Available for sale debt securities | 3,378,923,000 | 3,411,350,000
Equity Securities | 6,095,000 | 5,937,000
Total Amortized cost | 3,376,070,000 | 3,481,165,000
Total Gross unrealized gains |  | 9,459,000
Total Gross unrealized losses |  | 79,274,000
Available for sale debt securities and equity securities | 3,378,923,000 |
Assets/liabilities measured at fair value |  |
Available-for-sale securities |  |
Available for sale debt securities and equity securities | 3,378,923,000 | 3,411,350,000
Carrying Value |  |
Available-for-sale securities |  |
Available for sale debt securities and equity securities | 3,378,923,000 | 3,411,350,000
Residential mortgage-backed securities |  |
Available-for-sale securities |  |
Amortized cost, Available-for-sale securities | 3,285,623,000 | 3,295,366,000
Gross Unrealized Gains | 16,534,000 | 6,813,000
Gross Unrealized Losses | (16,609,000) | (79,169,000)
Residential mortgage-backed securities | Assets/liabilities measured at fair value |  |
Available-for-sale securities |  |
Available for sale debt securities | 3,285,548,000 | 3,223,010,000
Residential mortgage-backed securities | Carrying Value |  |
Available-for-sale securities |  |
Available for sale debt securities | 3,285,548,000 | 3,223,010,000
Mortgage-backed securities by Ginnie Mae |  |
Available-for-sale securities |  |
Available for sale debt securities | 571,247,000 | 501,293,000
Mortgage-backed securities by Fannie Mae and Freddie Mac |  |
Available-for-sale securities |  |
Available for sale debt securities | 2,714,301,000 | 2,721,717
Obligations of states and political subdivisions |  |
Available-for-sale securities |  |
Amortized cost, Available-for-sale securities | 90,447,000 | 185,799,000
Gross Unrealized Gains | 2,933,000 | 2,646,000
Gross Unrealized Losses | (5,000) | (105,000)
Obligations of states and political subdivisions | Assets/liabilities measured at fair value |  |
Available-for-sale securities |  |
Available for sale debt securities | 93,375,000 | 188,340,000
Obligations of states and political subdivisions | Carrying Value |  |
Available-for-sale securities |  |
Available for sale debt securities | 93,375,000 | 188,340,000
Other securities |  |
Held-to-maturity securities |  |
Amortized cost | 2,400,000 | 1,200,000
Estimated fair value | 2,400,000 | 1,200,000
Carrying Value | $ 2,400,000 | $ 1,200,000

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