SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)	1 Months Ended				3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2017	Mar. 31, 2017	Oct. 31, 2016	Jan. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2015
Stock Issued During Period, Shares, New Issues			5,750,000	2,750,000			1,148,466
Shares Issued, Price Per Share			$ 16.00	$ 20.00	$ 10.42		$ 10.42
Sale of Stock, Consideration Received on Transaction			$ 86,166,000	$ 51,174,000			$ 11,455,000
Sale of Stock, Consideration Received if Additional Shares are Issued		$ 60,000,000
Commission fee percentage on gross proceeds from sale of ATM shares		3.00%
Increase in revenue due to change in selling method					$ 4,377,000
Marketing and Advertising Expense					$ 2,489,000	$ 3,486,000	8,916,000	$ 10,492,000
Net cash used in investing activities							$ (818,000)	$ (2,636,000)
Accounting Standards Update 2016-18 And 2016-15 [Member]
Net cash used in investing activities									$ 16,000
Subsequent Event [Member]
Shares Issued, Price Per Share	$ 11.29
Sale of Stock, Consideration Received on Transaction	$ 19,646,000
Sale of Stock, Consideration Received if Additional Shares are Issued	$ 1,793,290