LEASES - Amounts Recognized in the Balance Sheet for Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Leases:
Operating lease right-of-use assets	$ 63,471	$ 63,869
Current portion of operating lease obligations	16,502	17,375
Operating lease obligations (non-current)	$ 51,867	$ 52,207
Weighted average remaining lease term	6 years	6 years
Weighted average discount rate	6.80%	6.70%
Finance Leases:
Property, plant and equipment, net	$ 5,305	$ 4,779
Current portion of long-term debt and finance lease obligations	663	337
Long-term debt and finance lease obligations	$ 5,129	$ 4,816
Weighted average remaining lease term	10 years	12 years
Weighted average discount rate	6.40%	6.20%

Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

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Amount, after accumulated amortization, of right-of-use asset from finance lease.

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Weighted average discount rate for finance lease calculated at point in time.

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Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

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Amount of lessee's right to use underlying asset under operating lease.

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Weighted average discount rate for operating lease calculated at point in time.

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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