Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quantenna
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Charged to Other Accounts		$ 14.0
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 357.9	347.5	$ 462.3
Charged (Credited) to Costs and Expenses	(43.1)	5.0	4.6
Charged to Other Accounts	11.0	16.6	15.8
Deductions/Write-offs	(75.9)	(11.2)	(135.2)
Balance at End of Period	$ 249.9	$ 357.9	$ 347.5

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09(Column B))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09(Column E))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690

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Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

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Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense.

+ References

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Amount of decrease in valuation and qualifying accounts and reserves.

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