Comprehensive Income - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Comprehensive Income
(Loss) gain on sale of available-for-sale securities, net	$ (50)		$ 0		$ (168)	$ 325
Salaries and benefits	(13,280)		(12,494)		(25,014)	(22,967)
Interest on investment securities - taxable	768		891		1,647	1,786
Income from continuing operations, before income taxes	19,926		3,596		23,915	6,887
Income tax expense	(4,995)		(765)		(5,792)	(1,462)
Net income	15,377	$ 3,192	2,831	$ 2,594	18,569	5,425
Amount reclassified from AOCI
Comprehensive Income
Net income	(329)		(56)		(130)	125
Available-for-sale securities | Amount reclassified from AOCI
Comprehensive Income
(Loss) gain on sale of available-for-sale securities, net	(50)		0		(168)	325
Income from continuing operations, before income taxes	(50)		0		(168)	325
Income tax expense	13		0		45	(88)
Net income	(37)		0		(123)	237
Defined benefit pension plan items | Amount reclassified from AOCI
Comprehensive Income
Salaries and benefits	(68)		(77)		(136)	(153)
Income from continuing operations, before income taxes	(68)		(77)		(136)	(153)
Income tax expense	18		21		37	41
Net income	(50)		(56)		(99)	(112)
Investment Hedge | Amount reclassified from AOCI
Comprehensive Income
Interest on investment securities - taxable	(332)		0		126	0
Income from continuing operations, before income taxes	(332)		0		126	0
Income tax expense	90		0		(34)	0
Net income	$ (242)		$ 0		$ 92	$ 0