Adoption of Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percentage of net sales accounted for using unit-of-delivery method	48.00%
Reduction in remaining performance obligations due to adoption of ASU 2014-09		$ (3,900.0)
ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting guidance	$ 37.6
ASU 2014-09 \| Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of change in accounting guidance	37.6
Effect of Adoption \| ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction in remaining performance obligations due to adoption of ASU 2014-09	$ 600.0

Revenue Recognition, Unit of Delivery, Percentage of Net Sales Revenue

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- Definition

Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

+ References

No definition available.

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- Definition

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+ References

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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=84173487&loc=SL51747714-108306

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130556-203045

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