Investment Securities - Held-to-Maturity and Available-for-Sale, Scheduled Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Securities Held-to-Maturity, Amortized Cost	$ 148,470	$ 142,634
Securities Held-to-Maturity, Gross Unrealized Gains	875	287
Securities Held-to-Maturity, Gross Unrealized Losses	(385)	(1,346)
Securities Held-to-Maturity, Fair Value	148,960	141,575
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Debt Securities, Fair Value	315,648	328,507
Debt Securities, Available-For-Sale And Held-To-Maturity, Amortized Cost	324,733	342,711
Securities Available-for-Sale, Gross Unrealized Gain	631	394
Securities Available-for-Sale, Gross Unrealized Loss	(9,716)	(14,598)
Securities Available-for-Sale, Fair Value	315,648	328,507
U.S. Government Corporations and Agencies [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Securities Held-to-Maturity, Amortized Cost, After 1 year to 5 years	6,997	6,996
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	(46)	(104)
Securities Held-to-Maturity, Fair Value, After 1 year to 5 years	6,951	6,892
Securities Held-to-Maturity, Amortized Cost	6,997	6,996
Securities Held-to-Maturity, Gross Unrealized Gains	0	0
Securities Held-to-Maturity, Gross Unrealized Losses	(46)	(104)
Securities Held-to-Maturity, Fair Value	6,951	6,892
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	10,067	15,108
Securities Available-for-Sale, Gross Unrealized Gains, Within 1 year	0	0
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	(41)	(90)
Securities Available-for-Sale, Fair Value, Within 1 year	10,026	15,018
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	302	303
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	(5)	(6)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	297	297
Securities Available-for-Sale, Amortized Cost	10,369	15,411
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	0	0
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(46)	(96)
Securities Available-for-Sale, Debt Securities, Fair Value	10,323	15,315
State and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	3,483	5,900
Securities Available-for-Sale, Gross Unrealized Gains, Within 1 year	6	4
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	0	(6)
Securities Available-for-Sale, Fair Value, Within 1 year	3,489	5,898
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	17,439	15,459
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	83	36
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(1)	(56)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	17,521	15,439
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	40,506	43,923
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	458	318
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	0	(163)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	40,964	44,078
Securities Available-for-Sale, Amortized Cost	61,428	65,282
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	547	358
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(1)	(225)
Securities Available-for-Sale, Debt Securities, Fair Value	61,974	65,415
Residential Mortgage Backed Securities [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Securities Held-to-Maturity, Amortized Cost, After 5 years to 10 years	11,005	11,573
Securities Held-to-Maturity, Gross Unrealized Gains, After 5 years to 10 years	23	0
Securities Held-to-Maturity, Gross Unrecognized Losses, After 5 years to 10 years	(54)	(135)
Securities Held-to-Maturity, Fair Value, After 5 years to 10 years	10,974	11,438
Securities Held-to-Maturity, Amortized Cost, Over 10 years	130,468	124,065
Securities Held-to-Maturity, Gross Unrealized Gain, Over 10 years	852	287
Securities Held-to-Maturity, Gross Unrealized Losses, Over 10 years	(285)	(1,107)
Securities Held-to-Maturity, Fair Value, After 10 Years	131,035	123,245
Securities Held-to-Maturity, Amortized Cost	141,473	135,638
Securities Held-to-Maturity, Gross Unrealized Gains	875	287
Securities Held-to-Maturity, Gross Unrealized Losses	(339)	(1,242)
Securities Held-to-Maturity, Fair Value	142,009	134,683
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	6,204	5,799
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	11	3
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(75)	(70)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	6,140	5,732
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	46,409	49,904
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	14	6
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	(711)	(1,381)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	45,712	48,529
Securities Available-for-Sale, Amortized Cost, Over 10 years	97,524	100,873
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	52	26
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(1,663)	(3,398)
Securities Available-for-Sale, Fair Value, Over 10 years	95,913	97,501
Securities Available-for-Sale, Amortized Cost	150,137	156,576
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	77	35
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(2,449)	(4,849)
Securities Available-for-Sale, Debt Securities, Fair Value	147,765	151,762
Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	1,589	1,677
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	0	0
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	(60)	(78)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	1,529	1,599
Securities Available-for-Sale, Amortized Cost, Over 10 years	1,260	1,305
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	0	0
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(3)	(16)
Securities Available-for-Sale, Fair Value, Over 10 years	1,257	1,289
Securities Available-for-Sale, Amortized Cost	2,849	2,982
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	0	0
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(63)	(94)
Securities Available-for-Sale, Debt Securities, Fair Value	2,786	2,888
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	8,299	7,806
Securities Available-for-Sale, Gross Unrealized Gains, Within 1 year	0	0
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	(42)	(68)
Securities Available-for-Sale, Fair Value, Within 1 year	8,257	7,738
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	16,512	18,508
Securities Available-for-Sale, Gross Unrealized Gains, After 1 year to 5 years	7	1
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(104)	(332)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	16,415	18,177
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	15,139	16,146
Securities Available-for-Sale, Gross Unrealized Gains, After 5 years to 10 years	0	0
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	(289)	(392)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	14,850	15,754
Securities Available-for-Sale, Amortized Cost, Over 10 years	60,000	60,000
Securities Available-for-Sale, Gross Unrealized Gains, Over 10 years	0	0
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(6,722)	(8,542)
Securities Available-for-Sale, Fair Value, Over 10 years	53,278	51,458
Securities Available-for-Sale, Amortized Cost	99,950	102,460
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	7	1
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(7,157)	(9,334)
Securities Available-for-Sale, Debt Securities, Fair Value	$ 92,800	$ 93,127