REVENUE - Adoption of ASC 606 Affect Prior Year (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jul. 01, 2018	Jun. 30, 2018	Sep. 30, 2017
ASSETS
Prepaid expenses and other current assets	$ 1,463	$ 1,180	$ 929	$ 1,056
Other assets	1,900	1,974	720	289
LIABILITIES
Deferred revenue	1,428	1,638	511	439
SHAREHOLDERS' EQUITY
Accumulated deficit	(238,692)	(232,372)	(232,748)	$ (223,635)
As Reported
ASSETS
Prepaid expenses and other current assets	1,210		929
Other assets	636		720
LIABILITIES
Deferred revenue	312		511
SHAREHOLDERS' EQUITY
Accumulated deficit	(239,092)		$ (232,748)
Adjustment | ASC 606
ASSETS
Prepaid expenses and other current assets	(253)	251
Other assets	(1,264)	1,254
LIABILITIES
Deferred revenue	(1,116)	1,127
SHAREHOLDERS' EQUITY
Accumulated deficit	$ (400)	$ 376