LEASES - Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases, Operating [Abstract]
Right-of-use lease assets	$ 282,746	$ 274,292	$ 0
Right-of-use lease liability, current	38,104	48,033	0
Right-of-use lease liability, long-term	270,564	251,867	0
Finance leases:
Right-of-use lease assets	49,380	30,891	30,891
Right-of-use lease liability, current	12,117	5,928	5,928
Right-of-use lease liability, long-term	$ 34,972	$ 19,262	$ 19,262