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Securities - Unrealized Loss Positions (Details) $ in Thousands | Jun. 30, 2018 USD ($) security | Dec. 31, 2017 USD ($) security
--- | --- | ---
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 64 | 26
Greater than 12 months in an unrealized loss position | security | 24 | 22
Total | security | 88 | 48
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 4,425 | $ 1,457
Greater than 12 months in an unrealized loss position | 5,282 | 3,216
Total | 9,707 | 4,673
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 212,683 | 102,830
Greater than 12 months in an unrealized loss position | 110,793 | 108,651
Total | $ 323,476 | $ 211,481
U.S. Treasury |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 1 | 1
Total | security | 1 | 1
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 128 | $ 55
Total | 128 | 55
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 3,876 | 3,947
Total | $ 3,876 | $ 3,947
U.S. government agencies |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 4 | 2
Total | security | 4 | 2
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 153 | $ 9
Total | 153 | 9
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 12,216 | 6,550
Total | $ 12,216 | $ 6,550
U.S. government agency mortgage-backed |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 7 | 4
Greater than 12 months in an unrealized loss position | security | 5 | 5
Total | security | 12 | 9
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 356 | $ 24
Greater than 12 months in an unrealized loss position | 248 | 141
Total | 604 | 165
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 8,968 | 5,501
Greater than 12 months in an unrealized loss position | 4,439 | 4,843
Total | $ 13,407 | $ 10,344
States and political subdivisions |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 43 | 13
Greater than 12 months in an unrealized loss position | security | 2 | 1
Total | security | 45 | 14
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 3,264 | $ 1,237
Greater than 12 months in an unrealized loss position | 1,271 | 27
Total | 4,535 | 1,264
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 141,455 | 45,985
Greater than 12 months in an unrealized loss position | 3,849 | 1,512
Total | $ 145,304 | $ 47,497
Corporate bonds |  |
Securities Available-for-Sale, Number of Securities |  |
Greater than 12 months in an unrealized loss position | security | 1 | 1
Total | security | 1 | 1
Securities Available-for-Sale, Unrealized Losses |  |
Greater than 12 months in an unrealized loss position | $ 6 | $ 11
Total | 6 | 11
Securities Available-for-Sale, Fair Value |  |
Greater than 12 months in an unrealized loss position | 198 | 332
Total | $ 198 | $ 332
Collateralized mortgage obligations |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 3 | 3
Greater than 12 months in an unrealized loss position | security | 9 | 8
Total | security | 12 | 11
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 399 | $ 31
Greater than 12 months in an unrealized loss position | 2,007 | 1,124
Total | 2,406 | 1,155
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 20,353 | 11,534
Greater than 12 months in an unrealized loss position | 37,782 | 40,219
Total | $ 58,135 | $ 51,753
Asset-backed securities |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 3 |
Greater than 12 months in an unrealized loss position | security | 6 | 7
Total | security | 9 | 7
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 65 |
Greater than 12 months in an unrealized loss position | 1,736 | $ 1,913
Total | 1,801 | 1,913
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 8,451 |
Greater than 12 months in an unrealized loss position | 56,539 | 61,745
Total | $ 64,990 | $ 61,745
Collateralized loan obligations |  |
Securities Available-for-Sale, Number of Securities |  |
Less than 12 months in an unrealized loss position | security | 3 | 3
Greater than 12 months in an unrealized loss position | security | 1 |
Total | security | 4 | 3
Securities Available-for-Sale, Unrealized Losses |  |
Less than 12 months in an unrealized loss position | $ 60 | $ 101
Greater than 12 months in an unrealized loss position | 14 |
Total | 74 | 101
Securities Available-for-Sale, Fair Value |  |
Less than 12 months in an unrealized loss position | 17,364 | 29,313
Greater than 12 months in an unrealized loss position | 7,986 |
Total | $ 25,350 | $ 29,313

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