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Securities (Tables) | 12 Months Ended
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Dec. 31, 2017
Securities |
Schedule of amortized cost and fair value of the securities portfolio and corresponding amounts of gross unrealized gains and losses recognized in accumulated other comprehensive loss |
|  |  |  |  | Gross |  | Gross |  |  |
|  | Amortized |  | Unrealized |  | Unrealized |  | Fair
December 31, 2017 |  | Cost |  | Gains |  | Losses |  | Value
Securities available-for-sale |  |  |  |  |  |  |  |
U.S. Treasuries |  | $ | 4,002 |  | $ | - |  | $ | (55) |  | $ | 3,947
U.S. government agencies |  |  | 13,062 |  |  | 8 |  |  | (9) |  |  | 13,061
U.S. government agencies mortgage-backed |  |  | 12,372 |  |  | 7 |  |  | (165) |  |  | 12,214
States and political subdivisions |  |  | 272,240 |  |  | 7,116 |  |  | (1,264) |  |  | 278,092
Corporate bonds |  |  | 823 |  |  | 21 |  |  | (11) |  |  | 833
Collateralized mortgage obligations |  |  | 66,892 |  |  | 202 |  |  | (1,155) |  |  | 65,939
Asset-backed securities |  |  | 113,983 |  |  | 862 |  |  | (1,913) |  |  | 112,932
Collateralized loan obligations |  |  | 54,271 |  |  | 251 |  |  | (101) |  |  | 54,421
Total securities available-for-sale |  | $ | 537,645 |  | $ | 8,467 |  | $ | (4,673) |  | $ | 541,439
|  |  |  |  | Gross |  | Gross |  |  |
|  | Amortized |  | Unrealized |  | Unrealized |  | Fair
December 31, 2016 |  | Cost |  | Gains |  | Losses |  | Value
Securities available-for-sale |  |  |  |  |  |  |  |  |  |  |  |
U.S. government agencies mortgage-backed |  | $ | 42,511 |  | $ | - |  | $ | (977) |  | $ | 41,534
States and political subdivisions |  |  | 68,718 |  |  | 258 |  |  | (273) |  |  | 68,703
Corporate bonds |  |  | 10,957 |  |  | 9 |  |  | (336) |  |  | 10,630
Collateralized mortgage obligations |  |  | 174,352 |  |  | 374 |  |  | (3,799) |  |  | 170,927
Asset-backed securities |  |  | 146,391 |  |  | 341 |  |  | (8,325) |  |  | 138,407
Collateralized loan obligations |  |  | 102,504 |  |  | 29 |  |  | (896) |  |  | 101,637
Total securities available-for-sale |  | $ | 545,433 |  | $ | 1,011 |  | $ | (14,606) |  | $ | 531,838
Schedule of fair value, amortized cost and weighted average yield of debt securities by contractual maturity along with securities not due at a single maturity date, primarily mortgage-backed securities (MBS), asset-backed securities, and collateralized loan obligations |
|  |  |  |  | Weighted |  |  |  |  |
|  | Amortized |  | Average |  |  | Fair |
Securities available-for-sale |  | Cost |  | Yield |  |  | Value |
Due in one year or less |  | $ | 6,200 |  | 2.41 | % |  | $ | 6,185 |
Due after one year through five years |  |  | 4,346 |  | 2.03 |  |  |  | 4,279 |
Due after five years through ten years |  |  | 6,013 |  | 3.29 |  |  |  | 6,234 |
Due after ten years |  |  | 273,568 |  | 2.95 |  |  |  | 279,235 |
|  |  | 290,127 |  | 2.93 |  |  |  | 295,933 |
Mortgage-backed and collateralized mortgage obligations |  |  | 79,264 |  | 2.94 |  |  |  | 78,153 |
Asset-backed securities |  |  | 113,983 |  | 2.56 |  |  |  | 112,932 |
Collateralized loan obligations |  |  | 54,271 |  | 4.32 |  |  |  | 54,421 |
Total securities available-for-sale |  | $ | 537,645 |  | 2.99 | % |  | $ | 541,439 |
Schedule of securities with unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position |
|  | Less than 12 months |  | 12 months or more |  |  |  |  |  |  |  |
December 31, 2017 |  | in an unrealized loss position |  | in an unrealized loss position |  | Total
|  | Number of |  | Unrealized |  | Fair |  | Number of |  | Unrealized |  | Fair |  | Number of |  | Unrealized |  | Fair
Securities available-for-sale |  | Securities |  | Losses |  | Value |  | Securities |  | Losses |  | Value |  | Securities |  | Losses |  | Value
U.S. Treasuries |  | 1 |  | $ | 55 |  | $ | 3,947 |  | - |  | $ | - |  | $ | - |  | 1 |  | $ | 55 |  | $ | 3,947
U.S. government agencies |  | 2 |  |  | 9 |  |  | 6,550 |  | - |  |  | - |  |  | - |  | 2 |  |  | 9 |  |  | 6,550
U.S. government agencies mortgage-backed |  | 4 |  |  | 24 |  |  | 5,501 |  | 5 |  |  | 141 |  |  | 4,843 |  | 9 |  |  | 165 |  |  | 10,344
States and political subdivisions |  | 13 |  |  | 1,237 |  |  | 45,985 |  | 1 |  |  | 27 |  |  | 1,512 |  | 14 |  |  | 1,264 |  |  | 47,497
Corporate bonds |  | - |  |  | - |  |  | - |  | 1 |  |  | 11 |  |  | 332 |  | 1 |  |  | 11 |  |  | 332
Collateralized mortgage obligations |  | 3 |  |  | 31 |  |  | 11,534 |  | 8 |  |  | 1,124 |  |  | 40,219 |  | 11 |  |  | 1,155 |  |  | 51,753
Asset-backed securities |  | - |  |  | - |  |  | - |  | 7 |  |  | 1,913 |  |  | 61,745 |  | 7 |  |  | 1,913 |  |  | 61,745
Collateralized loan obligations |  | 3 |  |  | 101 |  |  | 29,313 |  | - |  |  | - |  |  | - |  | 3 |  |  | 101 |  |  | 29,313
Total securities available-for-sale |  | 26 |  | $ | 1,457 |  | $ | 102,830 |  | 22 |  | $ | 3,216 |  | $ | 108,651 |  | 48 |  | $ | 4,673 |  | $ | 211,481
|  | Less than 12 months |  | 12 months or more |  |  |  |  |  |  |  |
December 31, 2016 |  | in an unrealized loss position |  | in an unrealized loss position |  | Total
|  | Number of |  | Unrealized |  |  | Fair |  | Number of |  | Unrealized |  |  | Fair |  | Number of |  | Unrealized |  |  | Fair
Securities available-for-sale |  | Securities |  | Losses |  |  | Value |  | Securities |  | Losses |  |  | Value |  | Securities |  | Losses |  |  | Value
U.S. government agencies mortgage-backed |  | 11 |  | $ | 957 |  | $ | 40,636 |  | 1 |  | $ | 20 |  | $ | 898 |  | 12 |  | $ | 977 |  | $ | 41,534
States and political subdivisions |  | 12 |  |  | 273 |  |  | 35,241 |  | - |  |  | - |  |  | - |  | 12 |  |  | 273 |  |  | 35,241
Corporate bonds |  | 1 |  |  | 183 |  |  | 4,817 |  | 2 |  |  | 153 |  |  | 5,328 |  | 3 |  |  | 336 |  |  | 10,145
Collateralized mortgage obligations |  | 16 |  |  | 3,402 |  |  | 117,752 |  | 7 |  |  | 397 |  |  | 18,109 |  | 23 |  |  | 3,799 |  |  | 135,861
Asset-backed securities |  | 4 |  |  | 328 |  |  | 17,604 |  | 12 |  |  | 7,997 |  |  | 107,112 |  | 16 |  |  | 8,325 |  |  | 124,716
Collateralized loan obligations |  | - |  |  | - |  |  | - |  | 12 |  |  | 896 |  |  | 81,613 |  | 12 |  |  | 896 |  |  | 81,613
Total securities available-for-sale |  | 44 |  | $ | 5,143 |  | $ | 216,050 |  | 34 |  | $ | 9,463 |  | $ | 213,060 |  | 78 |  | $ | 14,606 |  | $ | 429,110
Schedule of proceeds from sale and gross realized gains and losses on sale of securities |
|  |  | Years ended December 31,
Securities available-for-sale |  |  | 2017 |  | 2016 |  | 2015
Proceeds from sales of securities |  |  | $ | 232,462 |  | $ | 306,400 |  | $ | 70,176
Gross realized gains on securities |  |  |  | 2,367 |  |  | 1,675 |  |  | 106
Gross realized losses on securities |  |  |  | (1,893) |  |  | (3,888) |  |  | (284)
Securities realized gains (losses), net |  |  | $ | 474 |  | $ | (2,213) |  | $ | (178)
Income tax expense (benefit) on net realized gains (losses) |  |  | $ | 198 |  | $ | (882) |  | $ | (71)

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- Definition Tabular disclosure of the proceeds from sales of available-for-sale securities and the gross realized gains and gross realized losses that have been included in earnings as a result of those sales. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + Details
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