ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Summary of the changes in accumulated balances of other comprehensive income (loss)) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,394,910	$ 1,301,648	$ 1,127,193	$ 1,057,448	$ 1,301,648	$ 1,057,448
Other comprehensive income (loss), net of tax	1,375	3,373	(2,169)	(1,631)	4,748	(3,800)
Ending balance	1,462,757	1,394,910	1,161,749	1,127,193	1,462,757	1,161,749
Unrealized Gains (Losses) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		927		693	927	693
Other comprehensive income (loss) before reclassifications, net of taxes					1,976	(81)
Realized (gains) loss reclassified from accumulated other comprehensive income					(1,311)	1
Other comprehensive income (loss), net of tax					665	(80)
Ending balance	1,592		613		1,592	613
Unrealized Gains (Losses) on Derivatives Designated as Hedging Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(1,978)		925	(1,978)	925
Other comprehensive income (loss) before reclassifications, net of taxes					3,197	(4,604)
Realized (gains) loss reclassified from accumulated other comprehensive income					(417)	884
Other comprehensive income (loss), net of tax					2,780	(3,720)
Ending balance	802		(2,795)		802	(2,795)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	2,322	(1,051)	(13)	1,618	(1,051)	1,618
Other comprehensive income (loss) before reclassifications, net of taxes					5,173	(4,685)
Realized (gains) loss reclassified from accumulated other comprehensive income					(1,728)	885
Other comprehensive income (loss), net of tax	72	3,373	(2,169)	(1,631)	3,445	(3,800)
Ending balance	$ 2,394	$ 2,322	$ (2,182)	$ (13)	$ 2,394	$ (2,182)