LEASES - Balance Sheet Classification (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets:
Operating lease assets	$ 316,626		$ 0
Finance lease assets	972
Total leased assets	317,598	$ 384,187
Liabilities, Current [Abstract]
Current portion of operating lease liabilities	22,986
Finance lease, current	273
Liabilities, Noncurrent [Abstract]
Operating lease liabilities, less current portion	301,905		$ 0
Finance lease, noncurrent	508
Total lease liabilities	325,672	$ 389,403
Accumulated amortization of finance leases	$ 1,456