Investment Securities - Available for Sale (Details) $ in Thousands	Sep. 30, 2021 USD ($) security	Dec. 31, 2020 USD ($) security	Sep. 30, 2020 USD ($) security
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	$ 484,443	$ 357,497	$ 366,481
Gross Unrealized Gains	5,321	8,118	8,884
Gross Unrealized Losses	(2,864)	(328)	(437)
Available-for-Sale at Fair Value	486,900	365,287	374,928
Maturities of Debt Securities, at Amortized Cost:
Within One Year	125
From 1 - 5 Years	478,337
From 5 - 10 Years	5,981
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	132
From 1 - 5 Years	480,994
From 5 - 10 Years	5,774
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	265,227	29,926	43,829
12 Months or Longer	30,313	5,682	55,039
Total	$ 295,540	$ 35,608	$ 98,868
Number of Securities in a Continuous Loss Position | security	42	6	31
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 2,177	$ 74	$ 54
12 Months or Longer	687	254	383
Total	2,864	328	437
Collateral Pledged
Available-For-Sale Securities
Available-For-Sale Securities, Pledged as Collateral, at Fair Value	361,014	244,411	308,879
U.S. Government & Agency Obligations
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	110,001	65,002	35,001
Gross Unrealized Gains	96	184	184
Gross Unrealized Losses	(792)	(74)	(18)
Available-for-Sale at Fair Value	109,305	65,112	35,167
Maturities of Debt Securities, at Amortized Cost:
Within One Year	0
From 1 - 5 Years	110,001
From 5 - 10 Years	0
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	0
From 1 - 5 Years	109,305
From 5 - 10 Years	0
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	74,695	29,926	29,982
12 Months or Longer	29,513	0	0
Total	$ 104,208	$ 29,926	$ 29,982
Number of Securities in a Continuous Loss Position | security	14	4	4
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 305	$ 74	$ 18
12 Months or Longer	487	0	0
Total	792	74	18
U.S. Government & Agency Obligations | Agency Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	110,001	65,002	35,001
Available-for-Sale at Fair Value	109,305	65,112	35,167
State and Municipal Obligations
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	400	528	593
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	0	0	0
Available-for-Sale at Fair Value	400	528	593
Maturities of Debt Securities, at Amortized Cost:
Within One Year	0
From 1 - 5 Years	40
From 5 - 10 Years	360
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	0
From 1 - 5 Years	40
From 5 - 10 Years	360
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
Mortgage- Backed Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	373,042	290,967	329,887
Gross Unrealized Gains	5,225	7,934	8,700
Gross Unrealized Losses	(1,872)	(54)	(219)
Available-for-Sale at Fair Value	376,395	298,847	338,368
Maturities of Debt Securities, at Amortized Cost:
Within One Year	125
From 1 - 5 Years	368,296
From 5 - 10 Years	4,621
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	132
From 1 - 5 Years	371,649
From 5 - 10 Years	4,614
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	190,532	0	13,847
12 Months or Longer	0	4,882	54,239
Total	$ 190,532	$ 4,882	$ 68,086
Number of Securities in a Continuous Loss Position | security	27	1	26
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 1,872	$ 0	$ 36
12 Months or Longer	0	54	183
Total	1,872	54	219
Mortgage- Backed Securities | US Government Agencies Debt Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	10,119	12,696	69,575
Available-for-Sale at Fair Value	10,165	12,683	69,407
Mortgage- Backed Securities | US Government-sponsored Enterprises Debt Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	362,923	278,271	260,312
Available-for-Sale at Fair Value	366,230	286,164	268,961
Corporate and Other Debt Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	1,000	1,000	1,000
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	(200)	(200)	(200)
Available-for-Sale at Fair Value	800	800	800
Maturities of Debt Securities, at Amortized Cost:
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	1,000
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	800
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	0	0
12 Months or Longer	800	800	800
Total	$ 800	$ 800	$ 800
Number of Securities in a Continuous Loss Position | security	1	1	1
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 0	$ 0
12 Months or Longer	200	200	200
Total	$ 200	$ 200	$ 200