Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 21,632	$ 20,208	$ 61,600	$ 61,187
Securities:
Net change in unrealized gain on securities	6,940	(5,696)	22,002	18,274
Reclassification adjustment for net gains realized in net income	(1,679)	(1,586)	(5,553)	(9,964)
Net change in non-credit related other than temporary impairment	0	0	0	7
Income taxes	(2,084)	2,871	(6,433)	(3,364)
Other comprehensive income (loss) on securities	3,177	(4,411)	10,016	4,953
Derivatives used in cash flow hedging relationships:
Net change in unrealized loss on derivatives	17	844	(656)	(4,623)
Reclassification adjustment for net losses on derivatives realized in net income	308	492	1,005	1,463
Income taxes	(123)	(517)	(337)	1,155
Other comprehensive income (loss) on cash flow hedges	202	819	12	(2,005)
Other comprehensive income (loss)	3,379	(3,592)	10,028	2,948
TOTAL COMPREHENSIVE INCOME	$ 25,011	$ 16,616	$ 71,628	$ 64,135