XML 147 R101.htm IDEA: XBRL DOCUMENT v2.4.1.9

Schedule of Changes in Unrecognized Income Tax Benefits (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Beginning balance	$ 72.8us-gaap_UnrecognizedTaxBenefits	$ 29.2us-gaap_UnrecognizedTaxBenefits	$ 29.7us-gaap_UnrecognizedTaxBenefits
Increases in prior period tax positions	2.0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0.1us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0.2us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions
Decreases in prior period tax positions	(0.6)us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	(5.8)us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	(0.3)us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
Expiration of the statute of limitations	(0.5)us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	(0.7)us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	(2.0)us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
Settlements	(0.7)us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	(8.6)us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	(0.4)us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities
Interest and penalties, net	(0.3)us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	(1.8)us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	0.8us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Ending balance	73.4us-gaap_UnrecognizedTaxBenefits	72.8us-gaap_UnrecognizedTaxBenefits	29.2us-gaap_UnrecognizedTaxBenefits
unrecognized tax benefit [Line Items]
Income tax penalties and interest accrued	4.4us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Unrecognized tax benefits	73.4us-gaap_UnrecognizedTaxBenefits	72.8us-gaap_UnrecognizedTaxBenefits	29.2us-gaap_UnrecognizedTaxBenefits
Increases in current period tax positions	0.7us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	60.4us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1.2us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions
Unrecognized tax benefits that would impact effective tax rate	9us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Unrecognized tax benefits that will be recognized within 12 months of year end	62us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit
Temporary difference [Member]
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Ending balance	60.9us-gaap_UnrecognizedTaxBenefits / ati_UnrecognizedtaxbenefitAxis = ati_TemporarydifferenceMember	59.4us-gaap_UnrecognizedTaxBenefits / ati_UnrecognizedtaxbenefitAxis = ati_TemporarydifferenceMember
unrecognized tax benefit [Line Items]
Unrecognized tax benefits	$ 60.9us-gaap_UnrecognizedTaxBenefits / ati_UnrecognizedtaxbenefitAxis = ati_TemporarydifferenceMember	$ 59.4us-gaap_UnrecognizedTaxBenefits / ati_UnrecognizedtaxbenefitAxis = ati_TemporarydifferenceMember

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The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

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Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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