Investment Securities - Held to Maturity (Details)	9 Months Ended
	Sep. 30, 2021 USD ($) security	Dec. 31, 2020 USD ($) security	Sep. 30, 2020 USD ($) security
Schedule of Held-to-maturity Securities [Line Items]
Debt securities, available-for-sale, allowance for credit loss	$ 0
Held-To-Maturity Securities, at Amortized Cost	198,337,000	$ 218,405,000	$ 224,799,000
Gross Unrealized Gains	5,599,000	8,174,000	8,745,000
Gross Unrealized Losses	0	(3,000)	(43,000)
Held-To-Maturity Securities, at Fair Value	203,936,000	226,576,000	233,501,000
Maturities of Debt Securities, at Amortized Cost:
Within One Year	24,221,000
From 1 - 5 Years	157,459,000
From 5 - 10 Years	15,791,000
Over 10 Years	866,000
Maturities of Debt Securities, at Fair Value:
Within One Year	24,407,000
From 1 - 5 Years	162,185,000
From 5 - 10 Years	16,473,000
Over 10 Years	871,000
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	1,513,000	1,476,000
12 Months or Longer	0	0	0
Total	$ 0	$ 1,513,000	$ 1,476,000
Number of Securities in a Continuous Loss Position | security	0	4	4
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 3,000	$ 42,000
12 Months or Longer	0	0	1,000
Total	0	3,000	43,000
Debt securities, available-for-sale, allowance for credit loss, not to sell before recovery, credit loss, previously recorded, expense (reversal)	0
Debt securities, held-to-maturity, allowance for credit loss	0
Equity Securities	1,886,000	1,636,000	1,511,000
State and Municipal Obligations
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, at Amortized Cost	179,952,000	192,352,000	195,735,000
Gross Unrealized Gains	4,834,000	7,080,000	7,488,000
Gross Unrealized Losses	0	(3,000)	(43,000)
Held-To-Maturity Securities, at Fair Value	184,786,000	199,429,000	203,180,000
Maturities of Debt Securities, at Amortized Cost:
Within One Year	23,281,000
From 1 - 5 Years	140,014,000
From 5 - 10 Years	15,791,000
Over 10 Years	866,000
Maturities of Debt Securities, at Fair Value:
Within One Year	23,448,000
From 1 - 5 Years	143,994,000
From 5 - 10 Years	16,473,000
Over 10 Years	871,000
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	1,513,000	1,476,000
12 Months or Longer	0	0	0
Total	$ 0	$ 1,513,000	$ 1,476,000
Number of Securities in a Continuous Loss Position | security	0	4	4
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 3,000	$ 42,000
12 Months or Longer	0	0	1,000
Total	0	3,000	43,000
Mortgage-Backed Securities - Residential
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, at Amortized Cost	18,385,000	26,053,000	29,064,000
Gross Unrealized Gains	765,000	1,094,000	1,257,000
Gross Unrealized Losses	0	0	0
Held-To-Maturity Securities, at Fair Value	19,150,000	27,147,000	30,321,000
Maturities of Debt Securities, at Amortized Cost:
Within One Year	940,000
From 1 - 5 Years	17,445,000
From 5 - 10 Years	0
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	959,000
From 1 - 5 Years	18,191,000
From 5 - 10 Years	0
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	0	0
12 Months or Longer	0	0	0
Total	$ 0	$ 0	$ 0
Number of Securities in a Continuous Loss Position | security	0	0	0
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 0	$ 0
12 Months or Longer	0	0	0
Total	0	0	0
Fair Value, Measurements, Recurring
Unrealized Losses on Securities in a Continuous Loss Position:
Equity Securities	1,886,000	1,636,000	1,511,000
Collateral Pledged
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, Pledged as Collateral, at Fair Value	192,929,000	211,176,000	221,844,000
US Government Agencies Debt Securities | Mortgage-Backed Securities - Residential
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, at Amortized Cost	6,302,000	9,440,000	10,669,000
US Government Agencies Debt Securities | Fair Value, Measurements, Recurring | Mortgage-Backed Securities - Residential
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, at Fair Value	6,506,000	9,762,000	11,049,000
US Government-sponsored Enterprises Debt Securities | Mortgage-Backed Securities - Residential
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, at Amortized Cost	12,083,000	16,613,000	18,392,000
US Government-sponsored Enterprises Debt Securities | Fair Value, Measurements, Recurring | Mortgage-Backed Securities - Residential
Schedule of Held-to-maturity Securities [Line Items]
Held-To-Maturity Securities, at Fair Value	$ 12,644,000	$ 17,385,000	$ 19,272,000