Investment Securities, Securities in Continuous Unrealized Loss Position (Details)	3 Months Ended
	Mar. 31, 2021 USD ($) Security	Dec. 31, 2020 USD ($) Security	Mar. 31, 2020 USD ($) Security
Investment Securities, Qualitative Disclosure [Abstract]
Number of investment securities held | Security	599
Less than 12 months, number of positions | Security	83
12 months or more, number of positions | Security	88
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 310,295,000	$ 25,924,000	$ 3,961,000
12 months or more, fair value	7,201,000	6,303,000	4,929,000
Total, fair value	317,496,000	32,227,000	8,890,000
Less than 12 months, unrealized loss	10,789,000	66,000	7,000
12 months or more, unrealized loss	88,000	93,000	99,000
Total, unrealized loss	10,877,000	159,000	106,000
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	303,275,000		728,000
12 months or more, fair value	0		0
Total, fair value	303,275,000		728,000
Less than 12 months, unrealized loss	11,131,000		10,000
12 months or more, unrealized loss	0		0
Total, unrealized loss	$ 11,131,000		10,000
Number of HTM investments with gross unrealized losses | Security	0
Mortgage Backed Securities [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 303,275,000
12 months or more, fair value	0
Total, fair value	303,275,000
Less than 12 months, unrealized loss	11,131,000
12 months or more, unrealized loss	0
Total, unrealized loss	11,131,000
Obligations of States and Political Subdivisions [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value			728,000
12 months or more, fair value			0
Total, fair value			728,000
Less than 12 months, unrealized loss			10,000
12 months or more, unrealized loss			0
Total, unrealized loss	$ 0	$ 0	$ 10,000
Number of HTM investments with gross unrealized losses | Security	0
Percentage of portfolio rated at either issue or issuer level	100.00%
US Treasury Notes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
12 months or more, number of positions | Security	0	0	0
US Government Agency SBA [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 505,000	$ 1,741,000	$ 2,458,000
12 months or more, fair value	7,028,000	6,126,000	4,674,000
Total, fair value	7,533,000	7,867,000	7,132,000
Less than 12 months, unrealized loss	1,000	3,000	5,000
12 months or more, unrealized loss	85,000	90,000	93,000
Total, unrealized loss	$ 86,000	93,000	98,000
Less than 12 months, number of positions | Security	3
12 months or more, number of positions | Security	70
Mortgage Backed Securities [Member]
Investment Securities, Qualitative Disclosure [Abstract]
Less than 12 months, number of positions | Security	62
12 months or more, number of positions | Security	18
Total, unrealized loss	$ 21,200,000	48,000	8,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	277,832,000	20,142,000	1,503,000
12 months or more, fair value	173,000	177,000	255,000
Total, fair value	278,005,000	20,319,000	1,758,000
Less than 12 months, unrealized loss	10,077,000	45,000	2,000
12 months or more, unrealized loss	3,000	3,000	6,000
Total, unrealized loss	10,080,000	48,000	8,000
Corporate Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	31,958,000	4,041,000
12 months or more, fair value	0	0
Total, fair value	31,958,000	4,041,000
Less than 12 months, unrealized loss	711,000	18,000
12 months or more, unrealized loss	0	0
Total, unrealized loss	$ 711,000	$ 18,000	$ 0
Less than 12 months, number of positions | Security	18
12 months or more, number of positions | Security	0