CLOSURE AND POST-CLOSURE OBLIGATIONS (Details 2) (Asset retirement obligations)	12 Months Ended
Dec. 31, 2014
Fair value of future asset retirement obligations
Estimated inflation rate (as a percent)	2.60%
Weighted-average
Fair value of future asset retirement obligations
Credit-adjusted risk-free interest rate (as a percent)	5.90%

Risk-free interest rate assumption used in valuing an instrument.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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