PROPERTY AND EQUIPMENT - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Asset retired	$ 9,200	$ 5,000	$ 33,300
Asset retired accumulated depreciation	7,300	4,400	$ 32,600
Property and equipment, gross	971,685	772,129
Accumulated depreciation	513,120	469,449
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	412,631	396,891
Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	43,930	48,011
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Abandonment | Leasehold improvements
Property, Plant and Equipment [Line Items]
Impairment charges	500
Property and equipment, gross	22,400
Accumulated depreciation	$ 22,400
Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Abandonment | Software
Property, Plant and Equipment [Line Items]
Impairment charges		1,600
Property and equipment, gross		2,400
Accumulated depreciation		$ 800