Securities - Schedule of Marketable Securities in Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2018 USD ($) security	Dec. 31, 2017 USD ($) security
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	46	36
Available for sale, Less than 12 months Estimated fair value	19,724	29,417
Available for sale, Less than 12 months Unrealized loss	$ (536)	$ (294)
Available for sale, 12 months and greater, Estimated fair value	24,880	10,581
Available for sale, 12 months and greater, Unrealized loss	(1,256)	(436)
Available for sale, Total Estimated fair value	44,604	39,998
Available for sale, Total Unrealized loss	$ (1,792)	$ (730)
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	12	6
Held to maturity, Less than 12 months Estimated fair value	$ 2,324	$ 0
Held to maturity, Less than 12 months Unrealized loss	(39)	0
Held to maturity, 12 months and greater, Estimated fair value	6,824	7,455
Held to maturity, 12 months and greater, Unrealized loss	(442)	(253)
Held to maturity, Total Estimated fair value	9,148	7,455
Held to maturity, Total Unrealized loss	$ (481)	$ (253)
Equity securities:
Equity securities, Total number in a loss position \| security	3
Equity securities, Less than 12 months Estimated Fair Value	$ 92
Equity securities, Less than 12 months Unrealized Loss	(7)
Equity securities, 12 months and greater, Estimated fair value	898
Equity securities, 12 months and greater, Unrealized loss	(102)
Equity securities, Total Estimated fair value	990
Equity securities, Total Unrealized loss	$ 109
U.S. Government sponsored entities
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	5	5
Available for sale, Less than 12 months Estimated fair value	734	3,732
Available for sale, Less than 12 months Unrealized loss	$ (17)	$ (40)
Available for sale, 12 months and greater, Estimated fair value	4,843	1,958
Available for sale, 12 months and greater, Unrealized loss	(166)	(34)
Available for sale, Total Estimated fair value	5,577	5,690
Available for sale, Total Unrealized loss	$ (183)	$ (74)
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	2	2
Held to maturity, Less than 12 months Estimated fair value	$ 0	$ 0
Held to maturity, Less than 12 months Unrealized loss	0	0
Held to maturity, 12 months and greater, Estimated fair value	2,619	2,933
Held to maturity, 12 months and greater, Unrealized loss	(169)	(93)
Held to maturity, Total Estimated fair value	2,619	2,933
Held to maturity, Total Unrealized loss	$ (169)	$ (93)
State and political subdivisions
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	6	2
Available for sale, Less than 12 months Estimated fair value	2,029	476
Available for sale, Less than 12 months Unrealized loss	$ (70)	$ (6)
Available for sale, 12 months and greater, Estimated fair value	1,834	1,792
Available for sale, 12 months and greater, Unrealized loss	(139)	(50)
Available for sale, Total Estimated fair value	3,863	2,268
Available for sale, Total Unrealized loss	$ (209)	$ (56)
Residential mortgage-backed securities
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	29	22
Available for sale, Less than 12 months Estimated fair value	11,424	20,646
Available for sale, Less than 12 months Unrealized loss	$ (319)	$ (218)
Available for sale, 12 months and greater, Estimated fair value	14,427	4,028
Available for sale, 12 months and greater, Unrealized loss	(740)	(168)
Available for sale, Total Estimated fair value	25,851	24,674
Available for sale, Total Unrealized loss	$ (1,059)	$ (386)
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	8	2
Held to maturity, Less than 12 months Estimated fair value	$ 2,324	$ 0
Held to maturity, Less than 12 months Unrealized loss	(39)	0
Held to maturity, 12 months and greater, Estimated fair value	832	979
Held to maturity, 12 months and greater, Unrealized loss	(47)	(18)
Held to maturity, Total Estimated fair value	3,156	979
Held to maturity, Total Unrealized loss	$ (86)	$ (18)
Commercial mortgage-backed securities
Held to maturity at cost:
Held to maturity, Total number in a loss position \| security	2	2
Held to maturity, Less than 12 months Estimated fair value	$ 0	$ 0
Held to maturity, Less than 12 months Unrealized loss	0	0
Held to maturity, 12 months and greater, Estimated fair value	3,373	3,543
Held to maturity, 12 months and greater, Unrealized loss	(226)	(142)
Held to maturity, Total Estimated fair value	3,373	3,543
Held to maturity, Total Unrealized loss	$ (226)	$ (142)
Corporate and other securities
Available for sale at fair value:
Available for sale, Total number in a loss position \| security	6	7
Available for sale, Less than 12 months Estimated fair value	5,537	4,563
Available for sale, Less than 12 months Unrealized loss	$ (130)	$ (30)
Available for sale, 12 months and greater, Estimated fair value	3,776	2,803
Available for sale, 12 months and greater, Unrealized loss	(211)	(184)
Available for sale, Total Estimated fair value	9,313	7,366
Available for sale, Total Unrealized loss	$ (341)	$ (214)

Trading Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss

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Trading Securities, Continuous Unrealized Loss Position, Accumulated Loss

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Trading Securities, Securities In Unrealized Loss Positions, Qualitative Disclosure, Number Of Positions

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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.

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

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