Sales Contract liabilities (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 28, 2018	Sep. 28, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Deferred revenue - current	$ 241.6	$ 241.6	$ 213.4
Deferred revenue - noncurrent	91.7	91.7	86.9
Total contract liabilities	333.3	333.3	$ 300.3
Contract liabilities, revenue recognized	$ 20.0	$ 84.0

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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-Name Accounting Standards Codification
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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

+ References

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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