Acquisitions (Details) £ in Millions, $ in Millions					3 Months Ended
	Nov. 01, 2017 USD ($)	Jul. 03, 2017 USD ($)	Jan. 31, 2017 USD ($)	Jan. 31, 2017 GBP (£)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Jan. 31, 2017 GBP (£)
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill					$ 1,456.8		$ 1,452.1
Aggregate cash purchase price, net of cash acquired					0.7	$ 225.8
Accella Performance Materials
Acquisitions
Percentage of ownership interest acquired	100.00%
Total consideration	$ 671.4
Contribution to net sales since acquisition					106.5
Contribution to EBIT since acquisition					(1.6)
Unaudited pro forma revenue					860.4
Unaudited pro forma income from continuing operations					50.6
Additional depreciation and amortization related to fair value adjustments						$ 4.1
Total cash consideration transferred					671.4
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents					16.5
Receivables					66.8
Inventories					47.5
Prepaid expenses and other current assets					0.9
Property, plant and equipment					59.6
Definite-lived intangible assets					240.0
Other long-term assets					15.6
Accounts payable					(45.5)
Income tax payable					2.0
Accrued expenses					(23.2)
Other long-term liabilities					(15.6)
Deferred income tax liabilities					(83.5)
Total identifiable net assets					281.1
Goodwill					390.3
Gross contractual accounts receivable acquired	68.5
Receivables not expected to be acquired	1.7
Goodwill deductible for tax purposes	38.5
Indemnification asset	25.0
Accella Performance Materials | Acquired Technology
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired	$ 66.0
Accella Performance Materials | Acquired Technology | Minimum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	3 years
Accella Performance Materials | Acquired Technology | Maximum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	14 years
Accella Performance Materials | Customer relationships
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired	$ 146.0
Accella Performance Materials | Customer relationships | Minimum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	9 years
Accella Performance Materials | Customer relationships | Maximum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	12 years
Accella Performance Materials | Trade names
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired	$ 28.0
Accella Performance Materials | Trade names | Minimum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	4 years
Accella Performance Materials | Trade names | Maximum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	14 years
Accella Performance Materials | Balances Without Adoption of ASC 606
Acquisitions
Total cash consideration transferred	$ 670.7
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents	16.5
Receivables	66.8
Inventories	48.5
Prepaid expenses and other current assets	0.9
Property, plant and equipment	59.6
Definite-lived intangible assets	240.0
Other long-term assets	15.6
Accounts payable	(45.5)
Income tax payable	2.0
Accrued expenses	(23.2)
Other long-term liabilities	(15.6)
Deferred income tax liabilities	(83.5)
Total identifiable net assets	282.1
Goodwill	$ 388.6
Accella Performance Materials | Adjustment
Acquisitions
Total cash consideration transferred					0.7
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents					0.0
Receivables					0.0
Inventories					(1.0)
Prepaid expenses and other current assets					0.0
Property, plant and equipment					0.0
Definite-lived intangible assets					0.0
Other long-term assets					0.0
Accounts payable					0.0
Income tax payable					0.0
Accrued expenses					0.0
Other long-term liabilities					0.0
Deferred income tax liabilities					0.0
Total identifiable net assets					(1.0)
Goodwill					1.7
Drexel Metals, Inc.
Acquisitions
Percentage of ownership interest acquired		100.00%
Contribution to net sales since acquisition					12.0
Contribution to EBIT since acquisition					0.5
Recognized amounts of identifiable assets acquired and liabilities assumed:
Receivables		$ 5.3
Inventories		8.8
Definite-lived intangible assets		19.0
Accounts payable		(5.8)
Deferred income tax liabilities		(10.8)
Goodwill		26.9
Goodwill deductible for tax purposes		$ 0.0
Useful life of finite lived intangible assets		9 years
Aggregate cash purchase price, net of cash acquired		$ 55.8
Indefinite-lived intangible assets		$ 10.4
Arbo
Acquisitions
Percentage of ownership interest acquired			100.00%					100.00%
Contribution to net sales since acquisition					4.5
Contribution to EBIT since acquisition					$ 0.2
Recognized amounts of identifiable assets acquired and liabilities assumed:
Receivables			$ 1.5
Inventories			2.1
Definite-lived intangible assets			2.2
Accounts payable			(1.4)
Deferred income tax liabilities			(1.4)
Goodwill			4.7
Goodwill deductible for tax purposes			1.3
Aggregate cash purchase price, net of cash acquired			11.5	£ 9.1
Indefinite-lived intangible assets			1.6
Contingent consideration			$ 2.5					£ 2.0
Arbo | Customer relationships
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets			15 years	15 years