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Represents the current value of equity-based compensation awards not vested. Excludes stock and unit options.

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No definition available.

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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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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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No definition available.

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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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No definition available.

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Percentage of vesting of share-based compensation awards.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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EQUITY-BASED COMPENSATION - Performance-Based Restricted Stock Awards (Details) - Restricted Stock Awards - USD ($) $ / shares in Units, $ in Thousands						3 Months Ended
	Mar. 07, 2018	Apr. 18, 2017	Mar. 06, 2017	Mar. 08, 2016	Mar. 03, 2015	Mar. 31, 2018	Dec. 31, 2017
Performance-Based
Number of Shares
Non-vested at the beginning of period (in shares)						619,429
Granted (in shares)						397,808
Vested (in shares)						(309,010)
Non-vested at the end of period (in shares)						708,227
Weighted Average Grant Date Fair Value
Non-vested at the beginning of period (in dollars per share)						$ 16.16
Granted (in dollars per share)						15.69
Vested (in dollars per share)						18.78
Non-vested at the end of period (in dollars per share)						$ 14.75
Aggregate Current Value
Non-vested outstanding						$ 9,639	$ 9,434
Executive officers \| Performance-Based
Number of Shares
Granted (in shares)	243,303	30,322	180,039	254,563	154,505
Maximum \| Executive officers
Equity-based compensation
Number of shares may earn, as multiple of shares granted						200.00%
Minimum \| Executive officers
Equity-based compensation
Number of shares may earn, as multiple of shares granted						0.00%