Investment Securities, Securities in Continuous Unrealized Loss Position (Details)	9 Months Ended
	Sep. 30, 2020 USD ($) Security	Dec. 31, 2019 USD ($) Security	Sep. 30, 2019 USD ($) Security
Investment Securities, Qualitative Disclosure [Abstract]
Number of investment securities held | Security	568
Less than 12 months, number of positions | Security	20
12 months or more, number of positions | Security	82
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 33,416,000	$ 133,698,000	$ 224,669,000
12 months or more, fair value	6,004,000	5,911,000	6,655,000
Total, fair value	39,420,000	139,609,000	231,324,000
Less than 12 months, unrealized loss	137,000	94,000	154,000
12 months or more, unrealized loss	102,000	118,000	129,000
Total, unrealized loss	$ 239,000	212,000	283,000
Number of HTM investments with gross unrealized losses | Security	0
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value		355,000	212,000
12 months or more, fair value		0	0
Total, fair value		355,000	212,000
Less than 12 months, unrealized loss		12,000	7,000
12 months or more, unrealized loss		0	0
Total, unrealized loss		12,000	7,000
Obligations of States and Political Subdivisions [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value		355,000	212,000
12 months or more, fair value		0	0
Total, fair value		355,000	212,000
Less than 12 months, unrealized loss		12,000	7,000
12 months or more, unrealized loss		0	0
Total, unrealized loss	$ 0	12,000	7,000
Less than 12 months, number of positions | Security	0
12 months or more, number of positions | Security	0
Percentage of portfolio rated at either issue or issuer level	99.00%
Percentage of portfolio not rated	1.00%
US Treasury Notes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value			114,995,000
12 months or more, fair value			0
Total, fair value			114,995,000
Less than 12 months, unrealized loss			5,000
12 months or more, unrealized loss			0
Total, unrealized loss	$ 0	0	5,000
Less than 12 months, number of positions | Security	0
12 months or more, number of positions | Security	0
US Government Agency SBA [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 2,312,000	2,693,000	2,046,000
12 months or more, fair value	5,810,000	5,198,000	5,779,000
Total, fair value	8,122,000	7,891,000	7,825,000
Less than 12 months, unrealized loss	4,000	6,000	3,000
12 months or more, unrealized loss	98,000	107,000	112,000
Total, unrealized loss	$ 102,000	113,000	115,000
Less than 12 months, number of positions | Security	11
12 months or more, number of positions | Security	63
Mortgage Backed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 20,741,000	131,005,000	107,628,000
12 months or more, fair value	194,000	713,000	876,000
Total, fair value	20,935,000	131,718,000	108,504,000
Less than 12 months, unrealized loss	35,000	88,000	146,000
12 months or more, unrealized loss	4,000	11,000	17,000
Total, unrealized loss	$ 39,000	$ 99,000	$ 163,000
Less than 12 months, number of positions | Security	3
12 months or more, number of positions | Security	19
Corporate Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 10,363,000
12 months or more, fair value	0
Total, fair value	10,363,000
Less than 12 months, unrealized loss	98,000
12 months or more, unrealized loss	0
Total, unrealized loss	$ 98,000
Less than 12 months, number of positions | Security	6
12 months or more, number of positions | Security	0
Government Agency & Government-Sponsored Entities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of positions | Security	0	0	0
12 months or more, number of positions | Security	0	0	0