LONG-TERM DEBT / INTEREST EXPENSE - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Debt Instrument
Other	$ 721	$ (16)
Interest expense, net	(15,894)	(14,443)
Senior Credit Facility
Debt Instrument
Amortization of discount and debt issuance costs	625	592
Interest expense	11,432	10,874
Senior Credit Facility \| Revolving Credit Facility
Debt Instrument
Interest expense (excluding amortization)	1,289	616
Senior Credit Facility \| Term Loan Facility
Debt Instrument
Interest expense (excluding amortization)	9,518	9,666
1.5% Convertible Senior Notes, Due 2020 \| Convertible Senior Notes
Debt Instrument
Interest expense (excluding amortization)	1,078	1,078
Amortization of conversion feature	2,357	2,232
Amortization of discount and debt issuance costs	306	275
Interest expense	$ 3,741	$ 3,585

Amortization Of Conversion Feature

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- Definition

Other Interest Income (Expense), Nonoperating, Net

+ References

No definition available.

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- Definition

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

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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.

+ References

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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- Definition

Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph 8
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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The net amount of nonoperating interest income (expense).

+ References

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