SHAREHOLDERS EQUITY - Stock based compensation - Share Awards (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Stock issued (in shares)	6,127	0
Stock surrendered (in shares)	2,824
Stock surrendered to cover employee withholding taxes	$ 0.1
Time Vesting Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year	285,052
Granted (in shares)	0
Vested (in shares)	(8,951)
Forfeited (in shares)	(5,683)
Outstanding at end of year	270,418
Stock-based compensation expense	$ 0.4	$ 0.3
Unrecognized compensation expense	$ 3.4
Unrecognized compensation expense recognition period (in years)	1 year 8 months 12 days
Financial Performance Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year	152,430
Forfeited (in shares)	(2,044)
Outstanding at end of year	150,386
Market Performance Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of year	14,862
Outstanding at end of year	14,862
Unrecognized compensation expense	$ 0.4
Unrecognized compensation expense recognition period (in years)	1 year 3 months 18 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Vested (in shares)		0

The stock surrendered during the period.

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The value stock surrendered during the period.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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

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Number of shares issued during the period to an employee benefit plan, such as a defined contribution or defined benefit plan.

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