Comprehensive Income - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Comprehensive Income
Gain (loss) on sale of available-for-sale securities, net	$ 35			$ (11)			$ 865	$ (179)
Income from continuing operations, before income taxes	8,512			5,693			33,781	29,608
Income tax expense	(2,021)			(1,347)			(8,208)	(7,139)
Net income	6,491	$ 18,034	$ 1,048	4,327	$ 15,377	$ 3,192	25,573	22,896
Salaries and benefits	(10,519)			(15,438)			(49,360)	(40,452)
Interest on investment securities - taxable	411			689			1,554	2,336
Amount reclassified from AOCI
Comprehensive Income
Net income	(120)			(33)			940	(162)
Available-for-sale securities | Amount reclassified from AOCI
Comprehensive Income
Gain (loss) on sale of available-for-sale securities, net	35			(11)			865	(179)
Income from continuing operations, before income taxes	35			(11)			865	(179)
Income tax expense	(9)			2			(234)	48
Net income	26			(9)			631	(131)
Defined benefit pension plan items | Amount reclassified from AOCI
Comprehensive Income
Income from continuing operations, before income taxes	(105)			(68)			(315)	(204)
Income tax expense	28			18			85	55
Net income	(77)			(50)			(230)	(149)
Salaries and benefits	(105)			(68)			(315)	(204)
Investment Hedge | Amount reclassified from AOCI
Comprehensive Income
Income from continuing operations, before income taxes	(95)			36			738	162
Income tax expense	26			(10)			(199)	(44)
Net income	(69)			26			539	118
Interest on investment securities - taxable	$ (95)			$ 36			$ 738	$ 162