STOCKHOLDERS' EQUITY - AT MARKET ISSUANCE SALES AGREEMENT (Details) - USD ($)		3 Months Ended
Aug. 28, 2015	Mar. 31, 2018
At Market Issuance Sales Agreements [Line Items]
Net cash proceeds from issuance of common stock after deducting sales commissions and offering costs		$ 1,553,000
2015 Sales Agreement
At Market Issuance Sales Agreements [Line Items]
Aggregate offering price of common stock	$ 50,000,000
Maximum commission rate (as a percent)	3.00%
Issuance of common stock in connection with at market offering (in shares)		776,788
Net cash proceeds from issuance of common stock after deducting sales commissions and offering costs		$ 1,553,000

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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