FINANCIAL INSTRUMENTS (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Derivative financial instruments
Interest expense on the interest rate swaps and options	$ 13.6	$ 16.5	$ 15.1
Interest rate swaps and options
Derivative financial instruments
Interest expense on the interest rate swaps and options	13.6	16.5	15.1
Recurring \| Level 2 \| Cash flow hedges \| Interest rate swaps
Derivative financial instruments
Fair value of derivative contracts, current liability		$ 13.8

The amount of net gains or losses on a cash flow hedge reclassified in the period to interest expense from accumulated other comprehensive income.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph b(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624171-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6887037&loc=d3e80784-113994

Name:	us-gaap_CashFlowHedgeGainLossReclassifiedToInterestExpenseNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration