FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Carrying value
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, net	$ (705,987)	$ (712,277)
Unamortized debt issuance costs	7,100	7,700
Fair value
Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, net	$ (710,692)	$ (725,700)

Amount of unamortized debt discount (premium) and debt issuance costs.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant