Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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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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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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

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SHARE-BASED AWARDS - Restricted shares activity (Details) - Vesting of restricted shares - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Restricted Shares
Unvested at the beginning	2,156	1,666
Granted		1,263
Vested	(636)	(773)
Unvested at the end	1,520	2,156	1,666
Average Grant-Date Fair Value
Unvested at the beginning (in dollars per share)	$ 5.98	$ 4.88
Granted (in dollars per share)		6.94
Vested (in dollars per share)	5.90	5.18
Unvested at the end (in dollars per share)	$ 6.01	$ 5.98	$ 4.88
Total intrinsic value of Restricted Shares vested		$ 1.5	$ 0.1	$ 0.3
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years