RETIREMENT PLAN AND POST-RETIREMENT BENEFITS, Fair Value of Plan Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Pension Benefits [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	$ 811,480		$ 729,940
Pension Benefits [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	44,226	[1]	29,698	[1]
Pension Benefits [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	153,435	[2]	141,894	[2]
Pension Benefits [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	110,837		91,631
Pension Benefits [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	64		59
Pension Benefits [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	842		0
Pension Benefits [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	438,127	[3]	438,508	[3]
Pension Benefits [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	55,037		40,992
Pension Benefits [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	(92)		35
Pension Benefits [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		573
Pension Benefits [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	9,004	[4]	(13,450)	[4]
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	279,100		334,842
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	4,795	[1]	0	[1]
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	52,204	[2]	141,917	[2]
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	110,837		91,631
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	64		59
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	842		0
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	98,311	[3]	111,866	[3]
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	3,135		2,784
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	(92)		35
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	9,004	[4]	(13,450)	[4]
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	532,380		395,098
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	39,431	[1]	29,698	[1]
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	101,231	[2]	(23)	[2]
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	339,816	[3]	326,642	[3]
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	51,902		38,208
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		573
Pension Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[4]	0	[4]
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[1]	0	[1]
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[2]	0	[2]
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[3]	0	[3]
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Pension Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[4]	0	[4]
Other Post-Retirement Benefits [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	93,196		93,648
Other Post-Retirement Benefits [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	2,861	[1]	2,678	[1]
Other Post-Retirement Benefits [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	45,048	[2]	50,235	[2]
Other Post-Retirement Benefits [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	2,409		2,397
Other Post-Retirement Benefits [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	1		2
Other Post-Retirement Benefits [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	18		0
Other Post-Retirement Benefits [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	41,469	[3]	37,600	[3]
Other Post-Retirement Benefits [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	1,196		1,072
Other Post-Retirement Benefits [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	(2)		1
Other Post-Retirement Benefits [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		15
Other Post-Retirement Benefits [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	196	[4]	(352)	[4]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	55,811		61,862
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	105	[1]	0	[1]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	42,848	[2]	50,235	[2]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	2,409		2,397
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	1		2
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	18		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	10,168	[3]	9,506	[3]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	68		73
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	(2)		1
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 1 [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	196	[4]	(352)	[4]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	37,385		31,786
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	2,756	[1]	2,678	[1]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	2,200	[2]	0	[2]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	31,301	[3]	28,094	[3]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	1,128		999
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		15
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 2 [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[4]	0	[4]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Cash and Cash Equivalents [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[1]	0	[1]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[2]	0	[2]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Equity Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Preferred Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0	[3]	0	[3]
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Fixed Income Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | International Future Contracts [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | U S Convertible Securities [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	0		0
Other Post-Retirement Benefits [Member] | Fair Value, Inputs, Level 3 [Member] | Administrative Trust [Member]
Fair value of plan assets [Abstract]
Fair value of plan assets	$ 0	[4]	$ 0	[4]

[1] Cash and cash equivalents consist of investment in commingled funds that are primarily comprised of money market holdings and marketable securities, U.S. Treasury bills and commercial paper valued and redeemable at cost.

[2] This category includes approximately 26% small and mid-cap and 74% broad market domestic equity investments.

[3] Level 1 investments are comprised of fixed income securities that primarily invest in U.S. Treasury bonds. Level 2 investments consist of commingled funds that track the Barclays Capital Long Government and Corporate Credit Index and the Barclays Capital Aggregate US Fixed Income Index.

[4] The administrative trust net assets/liabilities are primarily comprised of amounts payable to and from brokers for sold and purchased securities.