LEASES - Leased assets and liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Operating lease assets	$ 55,843	$ 57,396
Finance right-of-use lease assets	22,903	20,499
Total	78,746	77,895
Finance leased assets - accumulated amortization	4,000	2,700
Liabilities:
Operating lease, current	17,813	17,317
Finance lease, current	4,397	4,128
Long-term operating lease liabilities	38,092	39,954
Finance lease, long term	19,098	16,308
Total	$ 79,400	$ 77,707