LEASES - Balance Sheet Information (Details) - USD ($)	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases, Operating [Abstract]
Right-of-use lease assets	$ 289,932,000	$ 274,292,000	$ 0
Right-of-use lease liability, current	39,123,000	48,033,000	0
Right-of-use lease liability, long-term	277,744,000	251,867,000	0
Finance leases:
Right-of-use lease assets	28,460,000	30,891,000	30,891,000
Right-of-use lease liability, current	6,464,000	5,928,000	5,928,000
Right-of-use lease liability, long-term	$ 20,632,000	$ 19,262,000	$ 19,262,000