SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets, net	$ 49,130	$ 38,468
Deferred tax assets	56,064	107,940
Retained earnings (deficit)	204	(30,545)
Tax benefit from stock options exercised and restricted stock vesting	0	$ 7,241	$ 2,073
Reclassification [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets, net			$ (3,400)
ASU 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax benefit from stock options exercised and restricted stock vesting	3,200
ASU 2016-09 [Member] | Reclassification [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax assets	400
Retained earnings (deficit)	$ 400