CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net Income	$ 11,157	$ 50,037
Other comprehensive income:
Change in unrealized holding loss on securities held-to-maturity and transferred securities	34	19
Change in unrealized holding loss on securities available-for-sale	120	15
Change in pension and other postretirement obligations	302	425
Change in unrealized gain on derivative asset	315	0
Other comprehensive gain before income taxes	771	459
Deferred tax expense	346	207
Net other comprehensive income during the period	425	252
Total comprehensive income	$ 11,582	$ 50,289