OTHER COMPREHENSIVE INCOME - RECLASSIFICATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Significant amounts reclassified out of each component of AOCI
Noninterest Income	$ 24,923	$ 24,921
Interest expense on deposits	(1,879)	(1,392)
Interest expense on FHLB advances	(2,292)	(2,953)
Total interest expense	(4,445)	(4,581)
Income tax expense	(10,054)	(8,893)
NET INCOME	20,017	17,735
Unrealized loss on cash flow hedge | Reclassification out of Accumulated Other Comprehensive Income
Significant amounts reclassified out of each component of AOCI
Interest expense on deposits	(34)	(43)
Interest expense on FHLB advances	(32)	(44)
Total interest expense	(66)	(87)
Income tax expense	23	30
NET INCOME	$ (43)	$ (57)