Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable within one year (or the operating cycle, if longer).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

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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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Amount of cash paid related to share-based compensation liabilities.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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Percentage of vesting of share-based compensation awards.

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STOCK-BASED COMPENSATION (Retricted Stock and Restricted Stock Units) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liability associated with stock-based awardsurrent	$ 5,964,000	$ 5,900,000
Equity Classified Award \| Service Period \| Equity-Settled Award \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 81,000
Unrecognized compensation cost, period for recognition	1 year 7 months 16 days
Equity Classified Award \| Service Period \| Equity-Settled Award \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 32,100,000
Unrecognized compensation cost, period for recognition	1 year 10 months 21 days
Liability Classified Award \| Service Period \| Cash-Settled Award \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 19,691,000
Unrecognized compensation cost, period for recognition	1 year 10 months 29 days
Cash paid to settle awards	$ 3,811,000	0	$ 0
Liability Classified Award \| Service Period \| Cash-Settled Award \| Restricted Stock Units (RSUs) \| Deferred compensation due to employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liability associated with stock-based awardsurrent	$ 5,964,000	$ 2,111,000
Business acquisitions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Year One \| Business acquisitions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.30%
Year Two \| Business acquisitions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.30%
Year Three \| Business acquisitions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.30%