Securities - Reconciliation from Amortized Cost to Estimated Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available for sale:
Amortized cost	$ 47,762	$ 52,763
Gross unrealized gains	201	183
Gross unrealized losses	(1,250)	(659)
Estimated fair value	46,713	52,287
Held to maturity:
Amortized cost	14,875	16,307
Gross unrealized gains	211	292
Gross unrealized losses	(284)	(253)
Estimated fair value	14,802	16,346
Equity securities:
Amortized cost	2,394	1,262
Gross unrealized gains	0	15
Gross unrealized losses	(250)	(71)
Estimated fair value	2,144	1,206
U.S. Government sponsored entities
Available for sale:
Amortized cost	5,758	5,765
Gross unrealized gains	0	0
Gross unrealized losses	(116)	(74)
Estimated fair value	5,642	5,691
Held to maturity:
Amortized cost	2,527	3,026
Gross unrealized gains	0	0
Gross unrealized losses	(94)	(93)
Estimated fair value	2,433	2,933
State and political subdivisions
Available for sale:
Amortized cost	4,614	5,227
Gross unrealized gains	4	21
Gross unrealized losses	(120)	(56)
Estimated fair value	4,498	5,192
Held to maturity:
Amortized cost	951	1,113
Gross unrealized gains	110	144
Gross unrealized losses	0	0
Estimated fair value	1,061	1,257
Residential mortgage-backed securities
Available for sale:
Amortized cost	27,159	32,111
Gross unrealized gains	74	153
Gross unrealized losses	(620)	(386)
Estimated fair value	26,613	31,878
Held to maturity:
Amortized cost	3,312	3,958
Gross unrealized gains	17	59
Gross unrealized losses	(52)	(18)
Estimated fair value	3,277	3,999
Commercial mortgage-backed securities
Held to maturity:
Amortized cost	3,570	3,685
Gross unrealized gains	0	0
Gross unrealized losses	(138)	(142)
Estimated fair value	3,432	3,543
Corporate and other securities
Available for sale:
Amortized cost	10,231	9,660
Gross unrealized gains	123	9
Gross unrealized losses	(394)	(143)
Estimated fair value	9,960	9,526
Held to maturity:
Amortized cost	4,515	4,525
Gross unrealized gains	84	89
Gross unrealized losses	0	0
Estimated fair value	$ 4,599	$ 4,614

Trading Securities, Accumulated Unrecognized Holding Gain

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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