RETIREMENT ANNUITY AND GUARANTEED CONTINUOUS EMPLOYMENT PLANS (Pension Plan Assets by Level with the Fair Value Hierarchy) (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		$ 183,015	$ 735,082
Quoted Prices in Active Markets for Identical Assets (Level 1)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		71,199	33,419
Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		5,240	213,227
Cash and cash equivalents
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		71,199	9,162
Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		71,199	9,162
Corporate and other obligations
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		5,240	213,227
Corporate and other obligations | Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value		5,240	213,227
US Treasury Bond Securities [Member]
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			24,257
US Treasury Bond Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			24,257
Common trusts and 103-12 investments
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	[1]	$ 106,576	460,474
Private equity funds
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	[2]		$ 27,962

[1] Common trusts and 103-12 investments (collectively "Trusts") are comprised of a number of investment funds that invest in a diverse portfolio of assets including equity securities, corporate and governmental bonds, equity and credit indexes and money markets. Trusts are valued at the NAV as determined by their custodian. NAV represents the accumulation of the unadjusted quoted close prices on the reporting date for the underlying investments divided by the total shares outstanding at the reporting dates.

[2] Private equity funds consist of four funds seeking capital appreciation by investing in private equity investment partnerships and venture capital companies. Private equity fund valuations are based on the NAV of the underlying assets. Funds are comprised of unrestricted and restricted publicly traded securities and privately held securities. Unrestricted securities are valued at the closing market price on the reporting date. Restricted securities may be valued at a discount from such closing public market price, depending on facts and circumstances. Privately held securities are valued at fair value as determined by the fund directors and general partners.