REVENUES - Schedule of Adjustments to Previously Reported Financial Statements from the Adoption (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Prepaid expenses and other assets	$ 9,497	$ 15,487	$ 8,673
Deposits and other assets	12,050	22,249	11,015
LIABILITIES AND STOCKHOLDERS’ DEFICIT
Deferred revenues	4,696	4,112	4,861
Deferred tax liability	1,952	1,860	1,651
Other long-term liabilities	4,060	3,128	7,744
Accumulated deficit	(1,343,609)	(1,300,519)	(1,323,723)
Balances without Adoption of ASC 606
ASSETS
Prepaid expenses and other assets			8,673
Deposits and other assets			11,015
LIABILITIES AND STOCKHOLDERS’ DEFICIT
Deferred revenues	4,771		4,861
Deferred tax liability			1,651
Other long-term liabilities	4,060		7,744
Accumulated deficit	(1,343,534)		$ (1,323,723)
Effect of Change Higher/ (Lower) | Accounting Standards Update 2014-09
ASSETS
Prepaid expenses and other assets		6,814
Deposits and other assets		11,234
LIABILITIES AND STOCKHOLDERS’ DEFICIT
Deferred revenues	(75)	(749)
Deferred tax liability		209
Other long-term liabilities	0	(4,616)
Accumulated deficit	$ (75)	$ 23,204