EMPLOYEE BENEFIT PLANS - ASSUMPTIONS (DETAILS)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	4.65%	5.55%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2028
Qualified Defined Benefit [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	4.65%	5.55%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate	5.55%	5.85%	6.20%
Net period benefit costs, Weighted-average expected return on assets	7.75%	7.75%	7.75%
Qualified Defined Benefit [Member] | Minimum [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Rate of compensation increase	2.94%	2.99%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Rate of compensation increase	2.99%	2.99%	2.99%
Qualified Defined Benefit [Member] | Maximum [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Rate of compensation increase	4.17%	4.35%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Rate of compensation increase	4.35%	4.35%	4.35%
Nonqualified Defined Benefit [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Benefit obligations, Weighted-average discount rate	4.65%	5.55%
Benefit obligations, Rate of compensation increase	5.00%	5.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Weighted-average discount rate	5.55%	5.85%	6.20%
Net period benefit costs, Rate of compensation increase	5.00%	5.00%	5.00%
Medical, Prescription Drugs and Dental Costs [Member] | Postretirement Medical Benefits [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Ultimate assumed trend rate	4.70%
Medical Cost [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Assumed health care cost trend rate	8.60%
Prescription Drug Costs [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Assumed health care cost trend rate	8.60%
Dental Costs [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Assumed health care cost trend rate	5.00%
Vision Costs [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Assumed health care cost trend rate	4.00%
Vision Costs [Member] | Postretirement Medical Benefits [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Net period benefit costs, Ultimate assumed trend rate	4.00%