LEASES (Summary of operating lease assets and liabilities recorded on the balance sheet) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Operating lease assets and liabilities recorded on the balance sheet
Right-of-use assets - operating leases	$ 49,600	$ 50,320
Current portion of lease liabilities - operating leases	3,040	3,035
Lease liabilities - operating leases, net of current portion	53,401	$ 54,168
Total operating lease liabilities	$ 56,441
Weighted average remaining lease term (in years)	13 years 1 month 6 days