Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16265-109275

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- Definition

Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

+ References

No definition available.

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

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- Definition

Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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-Name Accounting Standards Codification

-Topic 805

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

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- Definition

The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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-Paragraph 13

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Acquisitions - Narrative (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			0 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 07, 2014	Jun. 12, 2014	Dec. 31, 2015
Business Acquisition [Line Items]
Cash consideration, net of cash acquired	$ 92.9	$ 0	$ 0
Goodwill	780.4us-gaap_Goodwill	727.9us-gaap_Goodwill
ATI Flowform [Member]
Business Acquisition [Line Items]
Percentage of company acquired				85.00%
Cash consideration, net of cash acquired				72.9
Noncontrolling interest held by others				15.00%
Acquisition costs				0.7
Intangible assets acquired				21.4
Weighted average life of acquired intangible assets				23 years
Goodwill				46.8
Hanard [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired	20.0				20.5
Intangible assets acquired					4.3
Weighted average life of acquired intangible assets					20 years
Goodwill					8.3
Hanard [Member] \| Forecast Payment [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired						$ 0.5