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Securities - Available-for-sale Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands | Sep. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, fair value, less than 12 months | $ 94,685 | $ 67,058
Available-for-sale, gross unrealized losses, less than 12 months | (2,936) | (475)
Available-for-sale, fair value, 12 months or greater | 49,116 | 50,580
Available-for-sale, gross unrealized losses, 12 months or greater | (2,112) | (1,312)
Securities available for sale | 143,801 | 117,638
Available-for-sale, gross unrealized losses, total | (5,048) | (1,787)
U.S. Government-sponsored enterprises (GSEs) [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, fair value, less than 12 months | 14,425 | 1,358
Available-for-sale, gross unrealized losses, less than 12 months | (575) | (1)
Available-for-sale, fair value, 12 months or greater | 13,559 | 13,420
Available-for-sale, gross unrealized losses, 12 months or greater | (568) | (431)
Securities available for sale | 27,984 | 14,778
Available-for-sale, gross unrealized losses, total | (1,143) | (432)
Municipal securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, fair value, less than 12 months | 31,075 | 3,418
Available-for-sale, gross unrealized losses, less than 12 months | (648) | (43)
Available-for-sale, fair value, 12 months or greater | 2,559 | 2,112
Available-for-sale, gross unrealized losses, 12 months or greater | (181) | (104)
Securities available for sale | 33,634 | 5,530
Available-for-sale, gross unrealized losses, total | (829) | (147)
Other debt securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, fair value, less than 12 months | 0 | 950
Available-for-sale, gross unrealized losses, less than 12 months | 0 | (24)
Available-for-sale, fair value, 12 months or greater | 924 | 0
Available-for-sale, gross unrealized losses, 12 months or greater | (52) | 0
Securities available for sale | 924 | 950
Available-for-sale, gross unrealized losses, total | (52) | (24)
Mortgage-backed securities (GSEs) [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Available-for-sale, fair value, less than 12 months | 49,185 | 61,332
Available-for-sale, gross unrealized losses, less than 12 months | (1,713) | (407)
Available-for-sale, fair value, 12 months or greater | 32,074 | 35,048
Available-for-sale, gross unrealized losses, 12 months or greater | (1,311) | (777)
Securities available for sale | 81,259 | 96,380
Available-for-sale, gross unrealized losses, total | $ (3,024) | $ (1,184)

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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. + References Reference 1: 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=82897076&loc=d3e27337-111563 + Details
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- Definition Amount of accumulated unrealized loss on 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 12 months or longer. + References Reference 1: 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=82897076&loc=d3e27337-111563 + Details
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