Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 10,315	$ 9,133	$ 21,426	$ 18,214
Other comprehensive income (loss):
Change in net unrealized holding gains (losses) on available-for-sale securities	(3,094)	4,280	(14,828)	5,351
Change in funded status of pension plan		4		9
Change in net unrealized loss on derivative instrument	(406)		(406)
Other comprehensive income (loss) before income taxes	(3,500)	4,284	(15,234)	5,360
Income tax expense (benefit)	(1,054)	1,798	(4,602)	2,250
Other comprehensive income (loss)	(2,446)	2,486	(10,632)	3,110
Comprehensive income	$ 7,869	$ 11,619	$ 10,794	$ 21,324