STOCK-BASED COMPENSATION - Activity (Details) - $ / shares	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Grant Modification 2016
Number of Shares
Granted (in shares)		137,000
Grant Modification 2017
Number of Shares
Granted (in shares)		51,096
Grant Modification 2018
Number of Shares
Granted (in shares)		261,463
Forfeited (in shares)	(76,198)
Grant Modification 2018 \| Market-based vesting
Number of Shares
Granted (in shares)		185,265
Restricted Stock
Number of Shares
Unvested restricted stock and restricted stock units at the beginning of the period (in shares)	321,142	215,956
Unvested restricted stock and restricted stock units at the end of the period (in shares)		321,142
Weighted-Average Grant Date Fair Value per Share
Unvested restricted stock at the beginning of the period (in dollars per share)	$ 1.95	$ 3.27
Unvested restricted stock at the end of the period (in dollars per share)		$ 1.95
Restricted Stock \| Service-based Restricted stock unit awards
Number of Shares
Unvested restricted stock and restricted stock units at the beginning of the period (in shares)	978,461	885,800
Granted (in shares)		658,484
Vested (in shares)		(463,502)
Forfeited (in shares)		(102,321)
Unvested restricted stock and restricted stock units at the end of the period (in shares)		978,461
Weighted-Average Grant Date Fair Value per Share
Unvested restricted stock at the beginning of the period (in dollars per share)	$ 2.22	$ 1.37
Granted (in dollars per share)		1.92
Vested (in dollars per share)		2.57
Forfeited (in dollars per share)		2.42
Unvested restricted stock at the end of the period (in dollars per share)		$ 2.22
Restricted Stock \| 2015 Plan
Number of Shares
Granted (in shares)		1,391,679
Restricted Stock \| 2015 Plan \| Service-based Restricted stock unit awards
Number of Shares
Granted (in shares)		658,484
Performance-Based Shares \| 2015 Plan
Number of Shares
Unvested restricted stock and restricted stock units at the beginning of the period (in shares)	643,783	547,133
Granted (in shares)		733,195
Forfeited (in shares)		(636,545)
Unvested restricted stock and restricted stock units at the end of the period (in shares)		643,783
Weighted-Average Grant Date Fair Value per Share
Unvested restricted stock at the beginning of the period (in dollars per share)	$ 2.03	$ 3.68
Granted (in dollars per share)		1.98
Forfeited (in dollars per share)		3.46
Unvested restricted stock at the end of the period (in dollars per share)		$ 2.03
Performance-Based Shares \| 2015 Plan \| Market-based vesting
Number of Shares
Unvested restricted stock and restricted stock units at the beginning of the period (in shares)	0	369,525
Vested (in shares)		(185,265)
Forfeited (in shares)		(184,260)
Unvested restricted stock and restricted stock units at the end of the period (in shares)		0
Weighted-Average Grant Date Fair Value per Share
Unvested restricted stock at the beginning of the period (in dollars per share)	$ 0	$ 1.73
Vested (in dollars per share)		1.82
Forfeited (in dollars per share)		1.63
Unvested restricted stock at the end of the period (in dollars per share)		$ 0

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Subparagraph (c)(2)(i)
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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