CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) [Abstract]
Net income	$ 10,537	$ 10,081	$ 71,782	$ 33,388
Other comprehensive income:
Change in unrealized holding loss on securities held-to-maturity and transferred securities	21	20	62	39
Change in unrealized holding gain on securities available-for-sale	107	(176)	169	(1,525)
Change in pension and other postretirement obligations	425	478	1,275	348
Change in unrealized loss on derivative liability	708	0	(249)	0
Other comprehensive gain (loss) before income taxes	1,261	322	1,257	(1,138)
Deferred tax expense (benefit)	568	146	566	(512)
Other comprehensive income (loss), net of tax	693	176	691	(626)
Total other comprehensive income	$ 11,230	$ 10,257	$ 72,473	$ 32,762