CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net Income	$ 11,782	$ 13,313	$ 38,848	$ 36,459
Other comprehensive income (loss):
Change in unrealized holding loss on securities held-to-maturity and transferred securities	0	1,235	0	1,299
Change in unrealized holding loss on securities available-for-sale	(2,774)	27	(7,011)	251
Change in pension and other postretirement obligations	287	355	728	1,012
Change in unrealized gain on derivatives	754	92	3,330	(326)
Other comprehensive gain (loss) before income taxes	(1,733)	1,709	(2,953)	2,236
Deferred tax expense (benefit)	(577)	773	(981)	1,008
Other comprehensive income (loss), net of tax	(1,156)	936	(1,972)	1,228
Total comprehensive income	$ 10,626	$ 14,249	$ 36,876	$ 37,687