CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net Income	$ 11,501	$ 14,745
Other comprehensive income (loss):
Change in holding gain (loss) on securities available-for-sale	4,687	(2,558)
Change in pension and other postretirement obligations	492	155
Change in gain (loss) on derivative assets	(3,284)	2,016
Other comprehensive gain (loss) before income taxes	1,895	(387)
Deferred tax expense (benefit)	627	(112)
Other comprehensive income (loss), net of tax	1,268	(275)
Total comprehensive income	$ 12,769	$ 14,470