ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Amounts Reclassified from AOCI
Interest expense	$ 7,622	$ 5,441	$ 14,447	$ 10,197
Income tax benefit	1,701	4,505	4,882	8,821
Amount Reclassified from Accumulated Other Comprehensive Income
Amounts Reclassified from AOCI
Total reclassifications, before income tax	(7,672)	(572)	(7,832)	(961)
Income tax benefit	2,231	234	2,278	393
Total reclassifications, net of income tax	(5,441)	(338)	(5,554)	(568)
Amount Reclassified from Accumulated Other Comprehensive Income | Realized losses on sale of available for sale securities
Amounts Reclassified from AOCI
Net securities losses	(7,921)	0	(7,921)	0
Amount Reclassified from Accumulated Other Comprehensive Income | Prior service credit
Amounts Reclassified from AOCI
Other operating expenses	19	19	38	38
Amount Reclassified from Accumulated Other Comprehensive Income | Transition obligation
Amounts Reclassified from AOCI
Other operating expenses	(1)	(7)	(2)	(14)
Amount Reclassified from Accumulated Other Comprehensive Income | Actuarial losses
Amounts Reclassified from AOCI
Other operating expenses	(113)	(125)	(226)	(251)
Amount Reclassified from Accumulated Other Comprehensive Income | Realized losses on cash flow hedges
Amounts Reclassified from AOCI
Interest expense	$ 344	$ (459)	$ 279	$ (734)