UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net income	$ 50,037	$ 11,778
Amortization and reversal of net unrealized loss on securities transferred from available-for-sale to held-to-maturity, net of tax expense of $5 and $11 during the three months ended March 31, 2016 and 2015, respectively	6	13
Reduction in non-credit component of other than temporary impairment ("OTTI"), net of deferred taxes of $4 during the three months ended both March 31, 2016 and 2015	4	4
Reclassification adjustment for securities sold during the period, net of income tax benefit of $(624) during the three months ended March 31, 2015 (reclassified from net gain on securities and other assets)	0	(762)
Net unrealized securities gains arising during the period, net of deferred tax expense of $7 and $19 during the three months ended March 31, 2016 and 2015, respectively	8	24
Change in pension and other postretirement obligations, net of deferred tax expense (benefit) of $191 and $(268) during the three months ended March 31, 2016 and 2015, respectively	234	(329)
Total other comprehensive income (loss)	252	(1,050)
Comprehensive Income	$ 50,289	$ 10,728