LONG-TERM DEBT / INTEREST EXPENSE - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Instrument
Other	$ (116)	$ 79	$ (142)	$ 60
Interest expense, net	24,456	35,732	82,376	90,448
Revolving Credit Facility
Debt Instrument
Interest expense (excluding amortization)	0	0	0	316
Senior Credit Facility
Debt Instrument
Amortization of discount and debt issuance costs	2,522	3,659	11,087	8,954
Interest expense	22,369	33,047	75,081	82,638
Senior Credit Facility \| FILO Term Loan \| Revolving Credit Facility
Debt Instrument
Interest expense (excluding amortization)	97	285	316	655
FILO Asset-based Term Loan Facility \| FILO Term Loan \| Term Loan
Debt Instrument
Interest expense (excluding amortization)	6,901	6,901	20,479	15,241
Notes \| Convertible Senior Notes
Debt Instrument
Interest expense (excluding amortization)	597	707	2,033	2,121
Amortization of conversion feature	1,413	1,655	4,725	4,898
Amortization of discount and debt issuance costs	193	244	679	731
Interest expense	2,203	2,606	7,437	7,750
Tranche B-1 \| Senior Credit Facility \| Term Loan Facility
Debt Instrument
Interest expense (excluding amortization)	0	1,755	928	11,496
Tranche B-2 \| Senior Credit Facility \| Term Loan Facility
Debt Instrument
Interest expense (excluding amortization)	$ 12,849	$ 20,447	$ 42,271	$ 45,976

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Other Interest Income (Expense), Nonoperating, Net

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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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.

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The net amount of nonoperating interest income (expense).

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