SIGNIFICANT ACCOUNTING POLICIES LETTERS OF CREDIT (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$ 82.6	$ 86.1

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant