COMMON STOCK AND STOCK INCENTIVE PLANS - Unvested Restricted Awards (Details) - 2017 Equity Incentive Plan $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares
Restricted stock awards
Vesting period	4 years
Restricted Stock
Restricted stock awards
Vesting period	4 years
Ratio for grant of stock awards that is deducted from the shares available for grant	0.01
Shares
Total nonvested restricted stock at the beginning of the period (in shares) \| shares	921	1,438
Granted (in shares) \| shares	789	76
Vested (in shares) \| shares	(379)	(364)
Forfeited (in shares) \| shares	(25)	(229)
Total nonvested restricted stock at the end of the period (in shares) \| shares	1,306	921
Fair value of restricted stock awards vested \| $	$ 0.9	$ 0.8
Weighted average grant date fair value
Total nonvested restricted stock at the beginning of the period (in dollars per share) \| $ / shares	$ 1.96	$ 2.28
Granted (in dollars per share) \| $ / shares	3.53	2.34
Vested (in dollars per share) \| $ / shares	2.37	2.27
Forfeited (in dollars per share) \| $ / shares	3.33	3.64
Total nonvested restricted stock at the end of the period (in dollars per share) \| $ / shares	$ 2.77	$ 1.96

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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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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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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