SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND PRACTICES - New Accounting Standards - Condensed Consolidated Financial Statements - Without Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
ASSETS
Prepaid expenses and other current assets	$ 25,129		$ 25,129		$ 17,950
LIABILITIES AND EQUITY
Retained earnings	51,039		51,039		$ 115,780
Statement of Operations [Abstract]
Revenues	290,856	$ 285,067	937,130	$ 883,877
Operating expenses	220,717	216,126	694,275	655,489
Benefit for income taxes	(4,977)	(12,066)	(7,331)	(18,141)
Net loss	(22,862)	$ (83,528)	(73,177)	$ (104,122)
Without adoption of ASC 606 | ASU 2014-09
ASSETS
Prepaid expenses and other current assets	20,216		20,216
LIABILITIES AND EQUITY
Retained earnings	46,126		46,126
Statement of Operations [Abstract]
Revenues	298,662		939,875
Operating expenses	221,027		693,139
Benefit for income taxes	(4,977)		(6,972)
Net loss	$ (15,366)		$ (69,655)