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Investment Securities - Investment Securities in Unrealized Loss Positions (Details) $ in Thousands | Mar. 31, 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 | 23 | 54
Held-to-maturity, less than 12 continuous months, Fair value | $ 4,587 | $ 14,152
Held-to-maturity, less than 12 continuous months, Unrealized loss | (15) | (41)
Held-to-maturity, greater than 12 continuous months, Fair value | 2,320 | 1,999
Held-to-maturity, greater than 12 continuous months, Unrealized loss | (7) | (1)
Held-to-maturity, Total Securities in a loss position, Fair value | 6,907 | 16,151
Held-to-maturity, Gross Unrealized Losses | (22) | (42)
Available-for-sale, less than 12 continuous months, Fair value | 45,536 | 221,857
Available-for-sale, less than 12 continuous months, Unrealized loss | (140) | (1,273)
Available-for-sale, greater than 12 continuous months, Fair value | 15,173 | 17,987
Available-for-sale, greater than 12 continuous months, Unrealized loss | (67) | (233)
Available-for-sale, Total Securities in a loss position, Fair Value | 60,709 | 239,844
Available-for-sale, Total Securities in a loss position, Unrealized loss | (207) | (1,506)
Marketable securities, less than 12 continuous months, Fair value | 50,123 | 236,009
Marketable securities, less than 12 continuous months, Unrealized loss | (155) | (1,314)
Marketable securities, greater than 12 continuous months, Fair value | 17,493 | 19,986
Marketable securities, greater than 12 continuous months, Unrealized loss | (74) | (234)
Marketable securities, Total Securities in a loss position, Fair value | 67,616 | 255,995
Marketable securities, Total Securities in a loss position, Unrealized loss | $ (229) | $ (1,548)
Number of investment securities in unrealized loss position longer than 12 months | security | 4 |
Number of investment securities in unrealized loss position less than 12 months | security | 19 |
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 | $ 21,435 |
Available-for-sale, less than 12 continuous months, Unrealized loss | (64) |
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 | 21,435 |
Available-for-sale, Total Securities in a loss position, Unrealized loss | (64) |
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 | 6,515 | $ 68,809
Available-for-sale, less than 12 continuous months, Unrealized loss | (16) | (454)
Available-for-sale, greater than 12 continuous months, Fair value | 2,986 | 0
Available-for-sale, greater than 12 continuous months, Unrealized loss | (31) | 0
Available-for-sale, Total Securities in a loss position, Fair Value | 9,501 | 68,809
Available-for-sale, Total Securities in a loss position, Unrealized loss | (47) | (454)
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 | 1,938 | 9,277
Available-for-sale, less than 12 continuous months, Unrealized loss | (12) | (80)
Available-for-sale, greater than 12 continuous months, Fair value | 0 | 3,158
Available-for-sale, greater than 12 continuous months, Unrealized loss | 0 | (64)
Available-for-sale, Total Securities in a loss position, Fair Value | 1,938 | 12,435
Available-for-sale, Total Securities in a loss position, Unrealized loss | (12) | (144)
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 | 0
Available-for-sale, less than 12 continuous months, Unrealized loss | 0 | 0
Available-for-sale, greater than 12 continuous months, Fair value | 2,219 | 1,989
Available-for-sale, greater than 12 continuous months, Unrealized loss | (4) | (39)
Available-for-sale, Total Securities in a loss position, Fair Value | 2,219 | 1,989
Available-for-sale, Total Securities in a loss position, Unrealized loss | (4) | (39)
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 | 9,967 | 164
Available-for-sale, less than 12 continuous months, Unrealized loss | (30) | 0
Available-for-sale, greater than 12 continuous months, Fair value | 9,968 | 2,374
Available-for-sale, greater than 12 continuous months, Unrealized loss | (32) | (15)
Available-for-sale, Total Securities in a loss position, Fair Value | 19,935 | 2,538
Available-for-sale, Total Securities in a loss position, Unrealized loss | (62) | (15)
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 | 212 | 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 | 212 | 145,951
Available-for-sale, Total Securities in a loss position, Unrealized loss | (1) | (826)
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 | 2,487 |
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 | 2,487 |
Available-for-sale, Total Securities in a loss position, Unrealized loss | (3) |
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 | 2,982 |
Available-for-sale, less than 12 continuous months, Unrealized loss | (14) |
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 | 2,982 |
Available-for-sale, Total Securities in a loss position, Unrealized loss | (14) |
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 | 1,057 | 8,297
Held-to-maturity, less than 12 continuous months, Unrealized loss | (12) | (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 | 1,057 | 8,297
Held-to-maturity, Gross Unrealized Losses | (12) | (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 | 3,530 | 3,523
Held-to-maturity, less than 12 continuous months, Unrealized loss | (3) | (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 | 3,530 | 5,522
Held-to-maturity, Gross Unrealized Losses | (3) | (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 | 2,320 | 0
Held-to-maturity, greater than 12 continuous months, Unrealized loss | (7) | 0
Held-to-maturity, Total Securities in a loss position, Fair value | 2,320 | 2,332
Held-to-maturity, Gross Unrealized Losses | $ (7) | $ (7)

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