PENSION, OTHER POST RETIREMENT BENEFIT AND PROFIT SHARING PLANS (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Change in benefit obligations:
Service cost	$ 9,670,000		$ 8,107,000		$ 7,449,000
Interest cost	8,104,000		8,327,000		7,676,000
Components of net periodic benefit cost:
Service cost	9,670,000		8,107,000		7,449,000
Interest cost	8,104,000		8,327,000		7,676,000
Expected return on assets	(11,263,000)		(14,864,000)		(14,032,000)
Amortization of unrecognized transition amount	18,000		18,000		18,000
Recognized prior service cost	(768,000)		31,000		341,000
Recognized net loss	4,868,000		3,264,000		2,218,000
Special termination benefit	300,000		0		0
Net periodic benefit cost	10,929,000		4,883,000		3,670,000
Pension Benefits [Member]
Change in benefit obligations:
Projected benefit obligations at beginning of year	182,362,000		156,595,000		134,892,000
Service cost	9,670,000		8,107,000		7,449,000
Interest cost	8,104,000		8,327,000		7,676,000
Amendments	300,000		(8,494,000)		0
Actuarial loss	22,417,000		22,253,000		11,457,000
Benefits paid	(8,232,000)		(4,197,000)		(4,879,000)
Administrative expenses paid	(817,000)		(229,000)		0
Projected benefit obligations at end of year	213,804,000		182,362,000		156,595,000
Change in plans assets:
Fair value of plans assets at beginning of year	195,004,000		197,536,000		180,217,000
Actual return on assets	16,631,000		1,347,000		21,488,000
Employer contributions	1,118,000		547,000		710,000
Benefits paid	(8,232,000)		(4,197,000)		(4,879,000)
Administrative expenses paid	(817,000)		(229,000)		0
Fair value of plans assets at end of year	203,704,000		195,004,000		197,536,000
Funded status:
Projected benefit obligations	(213,804,000)		(182,362,000)		(156,595,000)
Fair value of plans assets	203,704,000		195,004,000		197,536,000
Unrecognized transition amount	0		0		0
Unrecognized prior service cost	0		0		0
Unrecognized actuarial loss	0		0		0
Net amount recognized	(10,100,000)		12,642,000		40,941,000
Amounts recognized in the consolidated balance sheets consisted of:
Prepaid benefit cost	94,046,000		102,307,000		104,749,000
Accrued benefit liability	(22,123,000)		(20,572,000)		(18,678,000)
Intangible asset	0		0		0
Accumulated other comprehensive income adjustment	(82,023,000)		(69,093,000)		(45,130,000)
Net amount recognized	(10,100,000)		12,642,000		40,941,000
Pre-tax amounts recognized in accumulated other comprehensive income consisted of:
Net transition obligation	37,000		55,000
Net prior service (benefit) cost	(6,134,000)		(6,901,000)
Net actuarial loss	88,120,000		75,939,000
Total accumulated other comprehensive income	82,023,000		69,093,000		45,130,000
Net transition obligation that will be amortized into net periodic cost over the next fiscal year	18,000
Net prior service credit that will be amortized into net periodic cost over the next fiscal year	768,000
Net actuarial loss that will be amortized into net periodic cost over the next fiscal year	6,099,000
Components of net periodic benefit cost:
Service cost	9,670,000		8,107,000		7,449,000
Interest cost	8,104,000		8,327,000		7,676,000
Information related to the Company's defined benefit pension plans [Abstract]
Accumulated benefit obligation	205,298,000		172,439,000
Basic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
General information	The Basic Plan is a non-contributory defined benefit pension plan managed by a trustee covering substantially all full-time employees who have at least one year of service and have attained the age of 21. For such employees hired prior to January 1, 2006, benefits are based on years of service and the employee's compensation
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate (in hundredths)	4.05%		4.80%
Rate of compensation increase (in hundredths)	3.00%	[1]	2.00%	[1]
Rate of compensation increase used for next fiscal year (in hundredths)	3.00%
Rate of compensation increase used for year two and beyond (in hundredths)	3.00%
Weighted-average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate (in hundredths)	4.80%		5.50%		6.00%
Rate of compensation increase (in hundredths)	3.00%		3.00%		3.00%
Expected rate of return on plan assets (in hundredths)	6.00%		8.00%		8.00%
Restoration Plan and Supplemental Plan [Member]
Accumulated benefit obligations in excess of plan assets [Abstract]
Projected benefit obligation	32,659,000		26,712,000
Accumulated benefit obligation	31,154,000		25,409,000
Fair value of assets	$ 0		$ 0
Restoration Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
General information	The Restoration Plan provides for the payment of retirement benefits to certain participants in the Basic Plan.
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate (in hundredths)	3.65%		4.45%
Rate of compensation increase (in hundredths)	3.00%	[1]	2.00%	[1]
Rate of compensation increase used for next fiscal year (in hundredths)	3.00%
Rate of compensation increase used for year two and beyond (in hundredths)	3.00%
Weighted-average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate (in hundredths)	4.45%		5.15%		5.85%
Rate of compensation increase (in hundredths)	3.00%		3.00%		3.00%
Supplemental Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
General information	The Supplemental Plan is a non-qualified defined benefit supplemental retirement plan for certain key employees. Benefits commence when the employee retires and are payable over a period of ten years.
Weighted-average assumptions used to determine benefit obligation [Abstract]
Discount rate (in hundredths)	2.85%		3.85%
Rate of compensation increase (in hundredths)	3.00%	[1]	2.00%	[1]
Rate of compensation increase used for next fiscal year (in hundredths)	3.00%
Rate of compensation increase used for year two and beyond (in hundredths)	3.00%
Weighted-average assumptions used to determine net periodic benefit cost [Abstract]
Discount rate (in hundredths)	3.85%		4.50%		5.35%
Rate of compensation increase (in hundredths)	3.00%		3.00%		3.00%

[1] 3.00% rate of compensation increase used for 2012 and beyond.