Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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- Definition

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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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-SubTopic 10
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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

Number of shares (or other type of equity) forfeited during the period.

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No definition available.

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Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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STOCK-BASED COMPENSATION - Plans (Details) - USD ($) shares in Millions, $ in Millions		12 Months Ended
	May 19, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Apr. 15, 2016
Stock-Based Compensation
Shares issued		1.9
Number of issued shares forfeited		0.4
Number of shares of available for future issuance		1.2
Stock-based compensation expense		$ 12.9	$ 9.8	$ 11.1
Special Equity Plan
Stock-Based Compensation
Shares of common stock authorized for issuance under the share-based compensation plan	1.5
2016 Omnibus Incentive Plan
Stock-Based Compensation
Shares of common stock authorized for issuance under the share-based compensation plan		2.3			2.3
2010 Plan
Stock-Based Compensation
Shares of common stock authorized for issuance under the share-based compensation plan		0.4			0.4
Stock Options \| Special Equity Plan
Stock-Based Compensation
Shares issued	0.8
Performance-based stock awards \| Special Equity Plan
Stock-Based Compensation
Shares issued	0.3
Restricted stock units \| 2016 Omnibus Incentive Plan
Stock-Based Compensation
Unrecognized stock-based compensation expense related to non-vested stock		$ 11.8
Weighted- average period over which unrecognized stock-based compensation cost will be expensed		2 years 3 months 18 days