SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Recently Issued Accounting Pronouncements
Provision for income taxes	$ 234	$ 1,226	$ (681)	$ 2,331
Deferred Tax Assets, Net, Current					$ 1,730
ASU 2015-17
Recently Issued Accounting Pronouncements
Deferred Tax Assets, Net, Current	(2,600)		(2,600)
Deferred Tax Assets, Net, Noncurrent	$ 2,600		2,600
ASU 2016-09
Recently Issued Accounting Pronouncements
Provision for income taxes			$ 300