Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 27, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring Basis Financial Statement Captions [Line Items]
ASCO - purchase price	$ 650.0
Carrying amount and estimated fair value of long term debt
Carrying Amount	1,791.9	$ 1,052.7
Fair Value	1,774.2	1,067.5
Secured Debt Term A [Member]
Debt Instrument [Line Items]
Secured Debt, Current		24.9
Secured Long-term Debt, Noncurrent		435.8
Carrying amount and estimated fair value of long term debt
Carrying Amount	204.9	460.7
Fair Value	204.7	461.9
Senior Unsecured Notes Due 2021 [Member]
Carrying amount and estimated fair value of long term debt
Carrying Amount	298.4	0.0
Fair Value	299.0	0.0
Senior unsecured notes due 2022 [Member]
Carrying amount and estimated fair value of long term debt
Carrying Amount	0.0	294.8
Fair Value	0.0	304.6
SeniorUnsecuredNotesDueTwoThousandAndTwentySix [Member] [Member]
Carrying amount and estimated fair value of long term debt
Carrying Amount	297.5	297.2
Fair Value	284.3	301.0
Senior Unsecured Notes Due 2023 [Member]
Carrying amount and estimated fair value of long term debt
Carrying Amount	297.8	0.0
Fair Value	296.8	0.0
Senior Unsecured Notes Due 2028 [Member]
Carrying amount and estimated fair value of long term debt
Carrying Amount	693.3	0.0
Fair Value	$ 689.4	$ 0.0

ASCO - purchase price

No definition available.

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- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

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-SubTopic 10
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-Paragraph 12
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
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- Definition

Carrying value as of the balance sheet date of the portion of long-term, collateralized debt obligations due within one year or the operating cycle, if longer. Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-SubTopic 210
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- Definition

Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Section S99
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