FAIR VALUE MEASUREMENTS (Narrative) (Details) $ in Thousands	6 Months Ended
Jun. 30, 2021 USD ($) item	Jun. 30, 2020 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of Rabbi Trusts established \| item	2
Net gains (losses) of the Rabbi Trust investments	$ 3,382	$ (998)
Unrealized net gains (losses) of the Rabbi Trusts' investments	$ 3,028	$ (990)

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.

No definition available.

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration