Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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Subsequent Events (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Subsequent Events (Details) - USD ($) $ in Thousands	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018	Dec. 31, 2018
Subsequent Event [Line Items]
Goodwill and other asset impairment	$ 342,146	$ 0	$ 342,146	$ 0
Goodwill impairment	326,100		326,100
Assets	3,441,995		3,441,995		$ 3,779,321
Comprehensive income (loss)	(263,530)	$ 68,620	(183,811)	$ 129,727
Customer relationships
Subsequent Event [Line Items]
Impairment of intangible assets	14,400		14,100
Trademarks
Subsequent Event [Line Items]
Impairment of intangible assets	1,600		1,600
Grass Valley
Subsequent Event [Line Items]
Goodwill and other asset impairment	342,100
Goodwill impairment	326,100
Assets	491,800		491,800
Liabilities	194,000		$ 194,000
Comprehensive income (loss)	73,200
Grass Valley \| Customer relationships
Subsequent Event [Line Items]
Impairment of intangible assets	14,400
Grass Valley \| Trademarks
Subsequent Event [Line Items]
Impairment of intangible assets	$ 1,600