EMPLOYEE BENEFIT PLANS - 1% HIGHER OR LOWER TREND RATE IN HEALTH CARE (DETAILS) (Postretirement Medical Benefits [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Postretirement Medical Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Change in service and interest cost, 1% higher trend rate	$ 1.9	$ 1.8	$ 2.1
Change in service and interes cost, 1% lower trend rate	(1.7)	(1.5)	(1.7)
Change in year-end postretirement benefit obligation, 1% higher trend rate	14.4	16.0	14.4
Change in year-end postretirement benefit obligation, 1% lower trend rate	$ (12.5)	$ (13.8)	$ (12.4)

The effect of a one-percentage- point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph m

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration