Securities - Reconciliation from Amortized Cost to Estimated Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Available for sale at fair value:
Amortized cost	$ 54,847	$ 40,839
Gross unrealized gains	433	360
Gross unrealized losses	(455)	(631)
Securities available for sale	54,825	40,568
Held to maturity at cost:
Amortized cost	20,241	20,979
Gross unrealized gains	370	291
Gross unrealized losses	(162)	(302)
Estimated fair value	20,449	20,968
U.S. Government sponsored entities
Available for sale at fair value:
Amortized cost	5,768	3,744
Gross unrealized gains	8	2
Gross unrealized losses	(13)	(30)
Securities available for sale	5,763	3,716
Held to maturity at cost:
Amortized cost	3,270	3,530
Gross unrealized gains	0	0
Gross unrealized losses	(64)	(128)
Estimated fair value	3,206	3,402
State and political subdivisions
Available for sale at fair value:
Amortized cost	5,862	5,545
Gross unrealized gains	53	19
Gross unrealized losses	(38)	(62)
Securities available for sale	5,877	5,502
Held to maturity at cost:
Amortized cost	2,302	2,306
Gross unrealized gains	203	181
Gross unrealized losses	0	(1)
Estimated fair value	2,505	2,486
Residential mortgage-backed securities
Available for sale at fair value:
Amortized cost	34,934	21,547
Gross unrealized gains	350	339
Gross unrealized losses	(179)	(255)
Securities available for sale	35,105	21,631
Held to maturity at cost:
Amortized cost	4,386	4,799
Gross unrealized gains	98	98
Gross unrealized losses	(16)	(25)
Estimated fair value	4,468	4,872
Commercial mortgage-backed securities
Held to maturity at cost:
Amortized cost	3,741	3,796
Gross unrealized gains	0	0
Gross unrealized losses	(76)	(148)
Estimated fair value	3,665	3,648
Corporate and other securities
Available for sale at fair value:
Amortized cost	8,283	10,003
Gross unrealized gains	22	0
Gross unrealized losses	(225)	(284)
Securities available for sale	8,080	9,719
Held to maturity at cost:
Amortized cost	6,542	6,548
Gross unrealized gains	69	12
Gross unrealized losses	(6)	0
Estimated fair value	$ 6,605	$ 6,560

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Fair value of investments in debt securities classified as held-to-maturity.

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