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Investment Securities - Investment Securities in Unrealized Loss Positions (Details) $ in Thousands | Jun. 30, 2016 USD ($) security | Dec. 31, 2015 USD ($) security
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Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Number of investment securities other-than-temporarily impaired | security | 0 |
Number of investment securities in unrealized loss position | security | 10 | 54
Held-to-maturity, less than 12 continuous months, Fair value | $ 6,058 | $ 14,152
Held-to-maturity, less than 12 continuous months, Unrealized loss | (9) | (41)
Held-to-maturity, greater than 12 continuous months, Fair value | 0 | 1,999
Held-to-maturity, greater than 12 continuous months, Unrealized loss | 0 | (1)
Held-to-maturity, Total Securities in a loss position, Fair value | 6,058 | 16,151
Held-to-maturity, Gross Unrealized Losses | (9) | (42)
Available-for-sale, less than 12 continuous months, Fair value | 14,087 | 221,857
Available-for-sale, less than 12 continuous months, Unrealized loss | (7) | (1,273)
Available-for-sale, greater than 12 continuous months, Fair value | 2,811 | 17,987
Available-for-sale, greater than 12 continuous months, Unrealized loss | (5) | (233)
Available-for-sale, Total Securities in a loss position, Fair Value | 16,898 | 239,844
Available-for-sale, Total Securities in a loss position, Unrealized loss | (12) | (1,506)
Marketable securities, less than 12 continuous months, Fair value | 20,145 | 236,009
Marketable securities, less than 12 continuous months, Unrealized loss | (16) | (1,314)
Marketable securities, greater than 12 continuous months, Fair value | 2,811 | 19,986
Marketable securities, greater than 12 continuous months, Unrealized loss | (5) | (234)
Marketable securities, Total Securities in a loss position, Fair value | 22,956 | 255,995
Marketable securities, Total Securities in a loss position, Unrealized loss | $ (21) | (1,548)
Number of investment securities in unrealized loss position longer than 12 months | security | 1 |
Number of investment securities in unrealized loss position less than 12 months | security | 9 |
Mortgage-backed Securities, Issued by FHLMC and FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | $ 0 | 68,809
Available-for-sale, less than 12 continuous months, Unrealized loss | 0 | (454)
Available-for-sale, greater than 12 continuous months, Fair value | 0 | 0
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 | 0
Available-for-sale, Total Securities in a loss position, Fair Value | 0 | 68,809
Available-for-sale, Total Securities in a loss position, Unrealized loss | 0 | (454)
CMOs issued by FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 0 | 9,277
Available-for-sale, less than 12 continuous months, Unrealized loss | 0 | (80)
Available-for-sale, greater than 12 continuous months, Fair value | 2,811 | 3,158
Available-for-sale, greater than 12 continuous months, Unrealized loss | (5) | (64)
Available-for-sale, Total Securities in a loss position, Fair Value | 2,811 | 12,435
Available-for-sale, Total Securities in a loss position, Unrealized loss | (5) | (144)
CMOs issued by FHLMC |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 0 | 0
Available-for-sale, less than 12 continuous months, Unrealized loss | 0 | 0
Available-for-sale, greater than 12 continuous months, Fair value | 0 | 1,989
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 | (39)
Available-for-sale, Total Securities in a loss position, Fair Value | 0 | 1,989
Available-for-sale, Total Securities in a loss position, Unrealized loss | 0 | (39)
CMOs issued by GNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 0 | 164
Available-for-sale, less than 12 continuous months, Unrealized loss | 0 | 0
Available-for-sale, greater than 12 continuous months, Fair value | 0 | 2,374
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 | (15)
Available-for-sale, Total Securities in a loss position, Fair Value | 0 | 2,538
Available-for-sale, Total Securities in a loss position, Unrealized loss | 0 | (15)
Debentures of government- sponsored agencies |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 9,997 | 136,064
Available-for-sale, less than 12 continuous months, Unrealized loss | (1) | (713)
Available-for-sale, greater than 12 continuous months, Fair value | 0 | 9,887
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 | (113)
Available-for-sale, Total Securities in a loss position, Fair Value | 9,997 | 145,951
Available-for-sale, Total Securities in a loss position, Unrealized loss | (1) | (826)
Privately issued CMOs |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 182 |
Available-for-sale, less than 12 continuous months, Unrealized loss | (1) |
Available-for-sale, greater than 12 continuous months, Fair value | 0 |
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 |
Available-for-sale, Total Securities in a loss position, Fair Value | 182 |
Available-for-sale, Total Securities in a loss position, Unrealized loss | (1) |
Obligations of state and political subdivisions |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 1,918 |
Available-for-sale, less than 12 continuous months, Unrealized loss | (2) |
Available-for-sale, greater than 12 continuous months, Fair value | 0 |
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 |
Available-for-sale, Total Securities in a loss position, Fair Value | 1,918 |
Available-for-sale, Total Securities in a loss position, Unrealized loss | (2) |
Corporate bonds |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, less than 12 continuous months, Fair value | 1,990 |
Available-for-sale, less than 12 continuous months, Unrealized loss | (3) |
Available-for-sale, greater than 12 continuous months, Fair value | 0 |
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 |
Available-for-sale, Total Securities in a loss position, Fair Value | 1,990 |
Available-for-sale, Total Securities in a loss position, Unrealized loss | (3) |
Obligations of state and political subdivisions |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held-to-maturity, less than 12 continuous months, Fair value | 1,058 | 8,297
Held-to-maturity, less than 12 continuous months, Unrealized loss | (8) | (19)
Held-to-maturity, greater than 12 continuous months, Fair value | 0 | 0
Held-to-maturity, greater than 12 continuous months, Unrealized loss | 0 | 0
Held-to-maturity, Total Securities in a loss position, Fair value | 1,058 | 8,297
Held-to-maturity, Gross Unrealized Losses | (8) | (19)
Available-for-sale, less than 12 continuous months, Fair value |  | 4,557
Available-for-sale, less than 12 continuous months, Unrealized loss |  | (15)
Available-for-sale, greater than 12 continuous months, Fair value |  | 579
Available-for-sale, greater than 12 continuous months, Unrealized loss |  | (2)
Available-for-sale, Total Securities in a loss position, Fair Value |  | 5,136
Available-for-sale, Total Securities in a loss position, Unrealized loss |  | (17)
Corporate bonds |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held-to-maturity, less than 12 continuous months, Fair value | 5,000 | 3,523
Held-to-maturity, less than 12 continuous months, Unrealized loss | (1) | (15)
Held-to-maturity, greater than 12 continuous months, Fair value | 0 | 1,999
Held-to-maturity, greater than 12 continuous months, Unrealized loss | 0 | (1)
Held-to-maturity, Total Securities in a loss position, Fair value | 5,000 | 5,522
Held-to-maturity, Gross Unrealized Losses | (1) | (16)
Available-for-sale, less than 12 continuous months, Fair value |  | 2,986
Available-for-sale, less than 12 continuous months, Unrealized loss |  | (11)
Available-for-sale, greater than 12 continuous months, Fair value |  | 0
Available-for-sale, greater than 12 continuous months, Unrealized loss |  | 0
Available-for-sale, Total Securities in a loss position, Fair Value |  | 2,986
Available-for-sale, Total Securities in a loss position, Unrealized loss |  | (11)
MBS pass-through securities issued by FHLMC and FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held-to-maturity, less than 12 continuous months, Fair value | 0 | 2,332
Held-to-maturity, less than 12 continuous months, Unrealized loss | 0 | (7)
Held-to-maturity, greater than 12 continuous months, Fair value | 0 | 0
Held-to-maturity, greater than 12 continuous months, Unrealized loss | 0 | 0
Held-to-maturity, Total Securities in a loss position, Fair value | 0 | 2,332
Held-to-maturity, Gross Unrealized Losses | $ 0 | $ (7)

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- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 + Details
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