FINANCIAL INSTRUMENTS: (Tables)

6 Months Ended

Jun. 30, 2013

FINANCIAL INSTRUMENTS:

Schedule of carrying amount and estimated fair values of the Company's financial instruments

Consequently, such financial instruments are not included in the following table that provides information about the carrying amounts and estimated fair values of other financial instruments that are not measured at fair value in the condensed consolidated balance sheet as of June 30, 2013 and December 31, 2012 (in millions):

	As of June 30, 2013				As of December 31, 2012
	Carrying Value		Fair Value		Carrying Value		Fair Value
Liabilities:
Long-term debt	$	4,209.4	$	4,109.5	$	4,213.9	$	4,870.6

Schedule of fair values of assets and liabilities measured at fair value on a recurring basis

	Fair Value at: June 30, 2013 Using:								Fair Value at December 31, 2012 Using:
	Fair Value as of		Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs		Fair Value as of December		Quoted prices in active markets for identical assets		Significant other observable inputs		Significant unobservable inputs
Description	June 30, 2013		(Level 1)		(Level 2)		(Level 3)		31, 2012		(Level 1)		(Level 2)		(Level 3)
Assets:
Short term investment:
- Trading securities	$	386.8	$	386.8					$	127.8	$	127.8
- Available for sale debt securities:
Corporate bonds	0.4				$	0.4			0.4				$	0.4
Asset backed obligations	0.1				0.1				0.1				0.1
Mortgage backed securities	5.6				5.6				6.0				6.0
Accounts receivable:
- Derivatives — Not classified as hedges:
Provisionally priced sales:
Copper	30.1		30.1						70.8		70.8
Molybdenum	89.6		89.6		—		—		102.9		102.9		—		—
Total	$	512.6	$	506.5	$	6.1	$	—	$	308.0	$	301.5	$	6.5	$	—