CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net Income	$ 51,288	$ 51,882	$ 72,514
Other comprehensive income (loss):
Change in unrealized holding loss on securities held-to-maturity and transferred securities	0	1,299	85
Change in unrealized holding loss (gain) on securities available-for-sale	(3,096)	587	56
Change in pension and other postretirement obligations	548	2,758	1,841
Change in unrealized (loss) gain on derivative asset	(1,450)	794	3,228
Other comprehensive gain (loss) before income taxes	(3,998)	5,438	5,210
Deferred tax expense (benefit)	(1,260)	2,427	2,348
Other comprehensive income (loss), net of tax	(2,738)	3,011	2,862
Total comprehensive income	$ 48,550	$ 54,893	$ 75,376