Investment Securities - Held-to-Maturity and Available-for-Sale, Scheduled Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Securities Held-to-Maturity, Amortized Cost	$ 222,389		$ 192,052
Securities Held-to-Maturity, Gross Unrealized Gains	7,163		2,944
Securities Held-to-Maturity, Gross Unrealized Losses	0		(110)
Securities Held-to-Maturity, Fair Value	229,552		194,886
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Debt Securities, Fair Value	198,886		246,924
Debt Securities, Available-For-Sale And Held-To-Maturity, Amortized Cost	208,636		251,014
Securities Available-for-Sale,Gross Unrealized Gain	3,025		1,415
Securities Available-for-Sale, Gross Unrealized Loss	(11,878)		(5,505)
Securities Available-for-Sale, Fair Value	198,886		246,924
Debt securities, available-for-sale, allowance for credit loss	897
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 five year	6,998		6,997
Securities Held-to-Maturity, Gross Unrealized Gains, After 1 year to 5 years	229		66
Securities Held-to-Maturity, Gross Unrealized Losses, After 1 year to 5 years	0		0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Year Two Through Five	0
Securities Held-to-Maturity, Fair Value, After 1 year to 5 years	7,227		7,063
Securities Held-to-Maturity, Amortized Cost	6,998		6,997
Securities Held-to-Maturity, Gross Unrealized Gains	229		66
Securities Held-to-Maturity, Gross Unrealized Losses	0		0
Securities Held-to-Maturity, Fair Value	7,227		7,063
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	300		301
Securities Available-for-Sale,Gross Unrealized Gain, Within 1 year	0		0
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	0		(1)
Securities Available-for-Sale, Fair Value, Within 1 year	300		300
Securities Available-for-Sale, Amortized Cost	300		301
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	0		0
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	0		(1)
Securities Available-for-Sale, Debt Securities, Fair Value	300		300
Debt Securities, Available-for-sale, Allowance for Credit Loss, Within Twelve Months	0
Debt securities, available-for-sale, allowance for credit loss	0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Year Two Through Five	0
State and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	5,062		4,717
Securities Available-for-Sale,Gross Unrealized Gain, After 1 year to 5 years	35		23
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	0		0
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	5,097		4,740
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	25,305		29,563
Securities Available-for-Sale,Gross Unrealized Gain, After 5 years to 10 years	198		292
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	0		0
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	25,503		29,855
Securities Available-for-Sale, Amortized Cost	30,367		34,280
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	233		315
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	0		0
Securities Available-for-Sale, Debt Securities, Fair Value	30,600		34,595
Debt securities, available-for-sale, allowance for credit loss	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Two Through Five	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Six Through Ten	0
Residential Mortgage-Backed Securities [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Securities Held-to-Maturity Securities, Amortized Cost, After 5 years to 10 years	8,449		9,083
Securities Held-to-Maturity, Gross Unrealized Gains, After 5 years to 10 years	310		129
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	8,759		9,212
Securities Held-to-Maturity, Over 10 years	206,942		175,972
Securities Held-to-Maturity, Gross Unrealized Gain, Over 10 years	6,624		2,749
Securities Held-to-Maturity, Gross Unrealized Losses, Over 10 years	0		(110)
Securities Held-to-Maturity, Fair Value, After 10 years	213,566		178,611
Securities Held-to-Maturity, Amortized Cost	215,391		185,055
Securities Held-to-Maturity, Gross Unrealized Gains	6,934		2,878
Securities Held-to-Maturity, Gross Unrealized Losses	0		(110)
Securities Held-to-Maturity, Fair Value	222,325		187,823
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, After Five Years To Ten Years	0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Over 10 Years	0
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	185		304
Securities Available-for-Sale,Gross Unrealized Gain, Within 1 year	9		9
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	0		0
Securities Available-for-Sale, Fair Value, Within 1 year	194		313
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	136		611
Securities Available-for-Sale,Gross Unrealized Gain, After 1 year to 5 years	4		3
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	0		(1)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	140		613
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	2,534		36,893
Securities Available-for-Sale,Gross Unrealized Gain, After 5 years to 10 years	72		107
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	0		(21)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	2,606		36,979
Securities Available-for-Sale, Amortized Cost, Over 10 years	80,291		80,630
Securities Available-for-Sale,Gross Unrealized Gain, Over 10 years	2,192		378
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(1)		(453)
Securities Available-for-Sale, Fair Value, Over 10 years	82,482		80,555
Securities Available-for-Sale, Amortized Cost	83,146		118,438
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	2,277		497
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(1)		(475)
Securities Available-for-Sale, Debt Securities, Fair Value	85,422		118,460
Debt Securities, Available-for-sale, Allowance for Credit Loss, Within Twelve Months	0
Debt securities, available-for-sale, allowance for credit loss	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Two Through Five	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Six Through Ten	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, After Ten Years	0
Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	974		2,377
Securities Available-for-Sale,Gross Unrealized Gain, After 5 years to 10 years	4		6
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	0		(22)
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	978		2,361
Securities Available-for-Sale, Amortized Cost	974		2,377
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	4		6
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	0		(22)
Securities Available-for-Sale, Debt Securities, Fair Value	978		2,361
Debt securities, available-for-sale, allowance for credit loss	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Six Through Ten	0
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Abstract]
Securities Available-for-Sale, Amortized Cost, Within 1 year	4,503		6,012
Securities Available-for-Sale,Gross Unrealized Gain, Within 1 year	3		1
Securities Available-for-Sale, Gross Unrealized Losses, Within 1 year	(5)		(4)
Securities Available-for-Sale, Fair Value, Within 1 year	4,497		6,009
Securities Available-for-Sale, Amortized Cost, After 1 year to 5 years	28,847		29,606
Securities Available-for-Sale,Gross Unrealized Gain, After 1 year to 5 years	486		596
Securities Available-for-Sale, Gross Unrealized Losses, After 1 year to 5 years	(385)		(61)
Securities Available-for-Sale, Fair Value, After 1 year to 5 years	28,902		30,141
Securities Available-for-Sale, Amortized Cost, After 5 years to 10 years	499		0
Securities Available-for-Sale,Gross Unrealized Gain, After 5 years to 10 years	22		0
Securities Available-for-Sale, Gross Unrealized Losses, After 5 years to 10 years	0		0
Securities Available-for-Sale, Fair Value, After 5 years to 10 years	521		0
Securities Available-for-Sale, Amortized Cost, Over 10 years	60,000		60,000
Securities Available-for-Sale,Gross Unrealized Gain, Over 10 years	0		0
Securities Available-for-Sale, Gross Unrealized Losses, Over 10 years	(11,487)		(4,942)
Securities Available-for-Sale, Fair Value, Over 10 years	47,666		55,058
Securities Available-for-Sale, Amortized Cost	93,849		95,618
Securities Available-for-Sale, Debt Securities, Gross Unrealized Gain	511		597
Securities Available-for-Sale, Debt Securities, Gross Unrealized Losses	(11,877)		(5,007)
Securities Available-for-Sale, Debt Securities, Fair Value	81,586		91,208
Debt Securities, Available-for-sale, Allowance for Credit Loss, Within Twelve Months	4
Debt securities, available-for-sale, allowance for credit loss	897	$ 0	$ 0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Two Through Five	46
Debt Securities, Available-for-sale, Allowance for Credit Loss, Year Six Through Ten	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, After Ten Years	$ 847