Investment Securities - Held-to-Maturity and Available-for-Sale, Scheduled Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Held-to-maturity Securities [Abstract]
Securities Held-to-Maturity, Amortized Cost	$ 45,542	$ 24,881
Securities Held-to-Maturity, Gross Unrealized Gains	103	2
Securities Held-to-Maturity, Gross Unrealized Losses	(12)	(12)
Securities Held-to-Maturity, Fair Value	45,633	24,871
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost	401,915	451,311
Securities Available-for-Sale, Gross Unrealized Gain	2,152	1,777
Securities Available-for-Sale, Gross Unrealized Loss	(5,787)	(9,451)
Securities Available-for-Sale, Fair Value	398,280	443,637
U.S. Government Corporations and Agencies [Member]
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	1,499	15,000
Securities Available-for-Sale, Gross Unrealized Gains, Within 1 year	0	20
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	(3)	0
Securities Available-for-Sale, Fair Value, Within 1 year	1,496	15,020
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	15,634	17,265
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	0	0
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(40)	(19)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	15,594	17,246
Securities Available-for-Sale, Amortized Cost	17,133	32,265
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	0	20
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(43)	(19)
Securities Available-for-Sale, Debt Securities, Fair Value	17,090	32,266
State and Political Subdivisions [Member]
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	1,258	964
Securities Available-for-Sale, Gross Unrealized Gains, Within 1 year	4	0
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	0	(1)
Securities Available-for-Sale, Fair Value, Within 1 year	1,262	963
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	17,838	18,705
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	52	38
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(23)	(75)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	17,867	18,668
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	57,334	55,541
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	1,166	829
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	(16)	(426)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	58,484	55,944
Securities Available-for-Sale, Amortized Cost, Over 10 years	3,120	12,663
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	9	226
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(17)	(114)
Securities Available-for-Sale, Fair Value, Over 10 years	3,112	12,775
Securities Available-for-Sale, Amortized Cost	79,550	87,873
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	1,231	1,093
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(56)	(616)
Securities Available-for-Sale, Debt Securities, Fair Value	80,725	88,350
Residential Mortgage Backed Securities [Member]
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	4,814	6,086
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	33	0
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(6)	(66)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	4,841	6,020
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	58,482	23,479
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	14	0
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	(718)	(622)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	57,778	22,857
Securities Available-for-Sale, Amortized Cost, Over 10 years	113,530	174,388
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	133	99
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(1,712)	(4,794)
Securities Available-for-Sale, Fair Value, Over 10 years	111,951	169,693
Securities Available-for-Sale, Amortized Cost	176,826	203,953
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	180	99
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(2,436)	(5,482)
Securities Available-for-Sale, Debt Securities, Fair Value	174,570	198,570
Collateralized Mortgage Obligations [Member]
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost, Over 10 years	3,879	4,659
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	20	0
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(57)	(105)
Securities Available-for-Sale, Fair Value, Over 10 years	3,842	4,554
Securities Available-for-Sale, Amortized Cost	3,879	4,659
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	20	0
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(57)	(105)
Securities Available-for-Sale, Debt Securities, Fair Value	3,842	4,554
Corporate Bonds [Member]
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	9,015	250
Securities Available-for-Sale, Gross Unrealized Gains, Within 1 year	0	0
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	(3)	0
Securities Available-for-Sale, Fair Value, Within 1 year	9,012	250
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	33,302	35,923
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	87	34
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(67)	(241)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	33,322	35,716
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	15,176	15,193
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	43	0
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	(215)	(516)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	15,004	14,677
Securities Available-for-Sale, Amortized Cost, Over 10 years	60,000	60,000
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	0	27
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(2,909)	(2,472)
Securities Available-for-Sale, Fair Value, Over 10 years	57,091	57,555
Securities Available-for-Sale, Amortized Cost	117,493	111,366
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	130	61
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(3,194)	(3,229)
Securities Available-for-Sale, Debt Securities, Fair Value	114,429	108,198
Money Market Mutual Funds [Member]
Available-for-sale Securities [Abstract]
Securities Available-for-Sale, Amortized Cost	6,624	10,784
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	0	0
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	0	0
Securities Available-for-Sale, Debt Securities, Fair Value	6,624	10,784
Equity Securities [Member]
Available-for-sale Securities [Abstract]
Equity Securities Available-for-Sale, Amortized Cost	410	411
Equity Securities Available-for-Sale, Gross Unrealized Gains	591	504
Equity Securities Available-for-Sale, Gross Unrealized Loss	(1)	0
Equity Securities Available-for-Sale, Fair Value	1,000	915
U.S. Government Corporations and Agencies [Member]
Held-to-maturity Securities [Abstract]
Securities Held-to-Maturity, Amortized Cost, After 1 year to 5 years	6,995	0
Securities Held-to-Maturity, Gross Unrealized Gains, After 1 year to 5 years	0	0
Securities Held-to-Maturity, Gross Unrealized Losses, After 1 year to 5 years	(10)	0
Securities Held-to-Maturity, Fair Value, After 1 year to 5 years	6,985	0
Securities Held-to-Maturity, Amortized Cost	6,995	0
Securities Held-to-Maturity, Gross Unrealized Gains	0	0
Securities Held-to-Maturity, Gross Unrealized Losses	(10)	0
Securities Held-to-Maturity, Fair Value	6,985	0
Residential Mortgage Backed Securities [Member]
Held-to-maturity Securities [Abstract]
Securities Held-to-Maturity, Amortized Cost, After 5 years to 10 years	9,418	0
Securities Held-to-Maturity, Gross Unrealized Gains, After 5 years to 10 years	3	0
Securities Held-to-Maturity, Gross Unrecognized Losses, After 5 years to 10 years	0	0
Securities Held-to-Maturity, Fair Value, After 5 years to 10 years	9,421	0
Securities Held-to-Maturity, Amortized Cost, Over 10 years	29,129	5,071
Securities Held-to-Maturity, Gross Unrealized Gain, Over 10 years	100	0
Securities Held-to-Maturity, Gross Unrealized Losses, Over 10 years	(2)	(3)
Securities Held-to-Maturity, Fair Value, After 10 Years	29,227	5,068
Securities Held-to-Maturity, Amortized Cost	38,547	5,071
Securities Held-to-Maturity, Gross Unrealized Gains	103	0
Securities Held-to-Maturity, Gross Unrealized Losses	(2)	(3)
Securities Held-to-Maturity, Fair Value	38,648	5,068
Corporate Bonds [Member]
Held-to-maturity Securities [Abstract]
Securities Held-to-Maturity, Amortized Cost, Within 1 year	0	19,810
Securities Held-to-Maturity, Gross Unrealized Gains, Within 1 year	0	2
Securities Held-to-Maturity, Gross Unrealized Losses, Within 1 year	0	(9)
Securities Held-to-Maturity, Fair Value, Within 1 year	0	19,803
Securities Held-to-Maturity, Amortized Cost	0	19,810
Securities Held-to-Maturity, Gross Unrealized Gains	0	2
Securities Held-to-Maturity, Gross Unrealized Losses	0	(9)
Securities Held-to-Maturity, Fair Value	$ 0	$ 19,803