RETIREMENT ANNUITY AND GUARANTEED CONTINUOUS EMPLOYMENT PLANS (Pension Plan Assets by Level with the Fair Value Hierarchy) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	$ 939,995		$ 813,897		$ 749,456
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	0		112,933
Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	907,432		673,881
Significant Unobservable Inputs (Level 3)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	32,563		27,083
Corporate stock
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			107,763	[1]
Corporate stock | 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			107,763
Corporate stock | Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			0
Corporate stock | Significant Unobservable Inputs (Level 3)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			0
Cash and cash equivalents
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	4,686	[2]	5,170
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	0		5,170
Cash and cash equivalents | Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	4,686		0
Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	0		0
Corporate and other obligations
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			412	[3]
Corporate and other obligations | 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			0
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			412
Corporate and other obligations | Significant Unobservable Inputs (Level 3)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value			0
Common trusts and 103-12 investments
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	902,746	[2]	673,469	[2]
Common trusts and 103-12 investments | 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	0		0
Common trusts and 103-12 investments | Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	902,746		673,469
Common trusts and 103-12 investments | Significant Unobservable Inputs (Level 3)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	0		0
Private equity funds
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	32,563	[4]	27,083	[4]
Private equity funds | 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	0		0
Private equity funds | Significant Other Observable Inputs (Level 2)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	0		0
Private equity funds | Significant Unobservable Inputs (Level 3)
Pension plans' assets by level within the fair value hierarchy
Total assets at fair value	$ 32,563		$ 27,083

[1] This investment category includes publicly traded equity investments directly held by the plans. Investments are valued at the unadjusted quoted close prices reported on the reporting date.

[2] Common trusts and 103-12 investments 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 net asset value ("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.

[3] This investment category is composed of publicly traded bonds and asset backed securities which are valued at the quoted closing market prices on the reporting date.

[4] Private equity funds consist of four funds seeking capital appreciation by investing in private equity investment partnerships and venture capital companies. 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.