CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 33,710	$ 21,632	$ 84,857	$ 61,600
Securities:
Net change in unrealized gain (loss) on securities	(8,060)	6,940	(36,395)	22,002
Reclassification adjustment for net (gains)/losses realized in net income	145	(1,679)	(1,037)	(5,553)
Income taxes	2,078	(2,084)	9,586	(6,433)
Other comprehensive income (loss) on securities	(5,837)	3,177	(27,846)	10,016
Derivatives used in cash flow hedging relationships:
Net change in unrealized gain (loss) on derivatives	395	17	2,991	(656)
Reclassification adjustment for net losses on derivatives realized in net income	242	308	469	1,005
Income taxes	(79)	(123)	(682)	(337)
Other comprehensive income on cash flow hedges	558	202	2,778	12
Other comprehensive income (loss)	(5,279)	3,379	(25,068)	10,028
TOTAL COMPREHENSIVE INCOME	$ 28,431	$ 25,011	$ 59,789	$ 71,628