CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net Income	$ 13,313	$ 10,537	$ 36,459	$ 71,782
Other comprehensive income:
Change in unrealized holding loss on securities held-to-maturity and transferred securities	1,235	21	1,299	62
Change in unrealized holding loss on securities available-for-sale	27	107	251	169
Change in pension and other postretirement obligations	355	425	1,012	1,275
Change in unrealized gain on derivatives	92	708	(326)	(249)
Other comprehensive gain before income taxes	1,709	1,261	2,236	1,257
Deferred tax expense	773	568	1,008	566
Other comprehensive income, net of tax	936	693	1,228	691
Total comprehensive income	$ 14,249	$ 11,230	$ 37,687	$ 72,473