Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 41,555	$ 41,573	$ 35,122
Other comprehensive income (loss):
Change in net unrealized holding gains (losses) on available-for-sale securities	14,142	(8,485)	1,631
Change in funded status of pension plan	3,525	(4,316)	1,718
Change in net unrealized loss on derivative instruments	(3,289)	(1,130)
Other comprehensive income (loss) before income taxes	14,378	(13,931)	3,349
Income tax expense (benefit)	4,343	(4,222)	1,199
Other comprehensive income (loss)	10,035	(9,709)	2,150
Comprehensive income	$ 51,590	$ 31,864	$ 37,272