Securities - Composition of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	$ 770,393	$ 779,133
Marketable equity securities	3,300	5,150
Total Securities	773,693	784,283
Total Debt Securities Available-for-Sale, Amortized Cost	737,005	768,427
Gross Unrealized Gains	33,478	11,659
Gross Unrealized Losses	(90)	(953)
Fair Value	770,393	779,133
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	10,282	10,040
Total Debt Securities Available-for-Sale, Amortized Cost	9,980	9,969
Gross Unrealized Gains	302	71
Gross Unrealized Losses	0	0
Fair Value	10,282	10,040
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	82,904	157,697
Total Debt Securities Available-for-Sale, Amortized Cost	78,755	155,969
Gross Unrealized Gains	4,149	1,773
Gross Unrealized Losses	0	(45)
Fair Value	82,904	157,697
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	209,296	189,348
Total Debt Securities Available-for-Sale, Amortized Cost	202,975	186,879
Gross Unrealized Gains	6,410	2,773
Gross Unrealized Losses	(89)	(304)
Fair Value	209,296	189,348
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	67,778	22,418
Total Debt Securities Available-for-Sale, Amortized Cost	66,960	22,120
Gross Unrealized Gains	818	321
Gross Unrealized Losses	0	(23)
Fair Value	67,778	22,418
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	273,681	275,870
Total Debt Securities Available-for-Sale, Amortized Cost	258,875	273,771
Gross Unrealized Gains	14,806	2,680
Gross Unrealized Losses	0	(581)
Fair Value	273,681	275,870
Corporate Obligations
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	2,025	7,627
Total Debt Securities Available-for-Sale, Amortized Cost	2,021	7,603
Gross Unrealized Gains	5	24
Gross Unrealized Losses	(1)	0
Fair Value	2,025	7,627
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale	124,427	116,133
Total Debt Securities Available-for-Sale, Amortized Cost	117,439	112,116
Gross Unrealized Gains	6,988	4,017
Gross Unrealized Losses	0	0
Fair Value	$ 124,427	$ 116,133