LEASES - Balance Sheet Classification (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Leases [Abstract]
Finance Lease, Right-of-Use Asset, Accumulated Amortization	$ 1,283
Assets [Abstract]
Operating lease assets	377,799
Finance lease assets	1,045
Total leased assets	378,844	$ 384,187
Liabilities, Current [Abstract]
Current portion of operating lease liabilities	22,205
Finance lease, current	383
Liabilities, Noncurrent [Abstract]
Operating lease liabilities, less current portion	362,094
Finance lease, noncurrent	466
Total lease liabilities	385,148	$ 389,403
Amortization of finance lease assets	$ 67