XML 31 R29.htm IDEA: XBRL DOCUMENT v3.2.0.727

ASSET RETIREMENT OBLIGATION: (Tables)

6 Months Ended

Jun. 30, 2015

ASSET RETIREMENT OBLIGATION:

Summary of the asset retirement obligation activity

The following table summarizes the asset retirement obligation activity for the six months ended June 30, 2015 and 2014 (in millions):

		2015			2014
Balance as of January 1		$	116.1		$	124.8
Changes in estimates		—			26.7
Payments		(11.2		)	(3.6		)
Accretion expense		8.2			3.6
Balance as of June 30,		$	113.1		$	151.5

X

- References

No definition available.

+ Details

Name:	us-gaap_AssetRetirementObligationDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation.

+ References

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



-Publisher FASB



-Name Accounting Standards Codification



-Topic 410



-SubTopic 30



-Section 50



-Paragraph 5



-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13201-110859

+ Details

Name:	us-gaap_ScheduleOfChangeInAssetRetirementObligationTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration