EMPLOYEE SAVINGS AND BENEFIT PLANS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Compensation Plans
Beginning of period balance	$ 10,875	$ 10,137	$ 11,017
Deferred compensation assumed in Merger	27,057	0	0
Employee compensation deferrals	840	963	534
Employee compensation payments	(1,184)	(945)	(1,464)
Increase (decrease) in plan fair value	3,407	720	50
End of period balance	40,995	10,875	10,137
Company's contribution to the 401K Plan
401(K) savings plan expense	$ 2,900	$ 1,000	$ 900