Investment Securities, Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) Security	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)
Investment Securities, Qualitative Disclosure [Abstract]
Number of investment securities held | Security	595
Less than 12 months, number of positions | Security	26
12 months or more, number of positions | Security	74
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 224,669	$ 180,524	$ 271,523
Less than 12 months, unrealized loss	154	563	6,124
12 months or more, fair value	6,655	255,418	111,641
12 months or more, unrealized loss	129	4,888	3,471
Total, fair value	231,324	435,942	383,164
Total, unrealized loss	283	5,451	9,595
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	212	6,052	15,309
Less than 12 months, unrealized loss	7	23	174
12 months or more, fair value	0	849	0
12 months or more, unrealized loss	0	16	0
Total, fair value	212	6,901	15,309
Total, unrealized loss	$ 7	39	174
Number of HTM investments with gross unrealized losses | Security	0
Obligations of States and Political Subdivisions [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 212	6,052	15,309
Less than 12 months, unrealized loss	7	23	174
12 months or more, fair value	0	849	0
12 months or more, unrealized loss	0	16	0
Total, fair value	212	6,901	15,309
Total, unrealized loss	$ 7	39	174
Less than 12 months, number of positions | Security	1
12 months or more, number of positions | Security	0
Municipal Bonds [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Percentage of bank qualified municipal bond portfolio rated	99.00%
Percentage of portfolio not rated	1.00%
Government Agency & Government-Sponsored Entities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, number of positions | Security	0
12 months or more, number of positions | Security	0
US Treasury Notes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 114,995	124,985	84,315
Less than 12 months, unrealized loss	5	7	290
12 months or more, fair value	0	39,529	24,902
12 months or more, unrealized loss	0	151	173
Total, fair value	114,995	164,514	109,217
Total, unrealized loss	$ 5	158	463
Less than 12 months, number of positions | Security	3
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	$ 2,046	3,250	4,965
Less than 12 months, unrealized loss	3	28	62
12 months or more, fair value	5,779	8,618	8,467
12 months or more, unrealized loss	112	132	115
Total, fair value	7,825	11,868	13,432
Total, unrealized loss	$ 115	160	177
Less than 12 months, number of positions | Security	13
12 months or more, number of positions | Security	53
Mortgage Backed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 107,628	52,289	182,243
Less than 12 months, unrealized loss	146	528	5,772
12 months or more, fair value	876	207,271	78,272
12 months or more, unrealized loss	17	4,605	3,183
Total, fair value	108,504	259,560	260,515
Total, unrealized loss	$ 163	$ 5,133	$ 8,955
Less than 12 months, number of positions | Security	9
12 months or more, number of positions | Security	21