Discontinued Operations - Operating Results of the Disposal Group (Details) - Grass Valley - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges	$ (521,400)
Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	360,496	$ 419,666	$ 301,458
Cost of sales	(208,173)	(241,164)	(169,025)
Gross profit	152,323	178,502	132,433
Selling, general and administrative expenses	(93,796)	(114,567)	(71,280)
Research and development expenses	(37,172)	(49,033)	(45,582)
Amortization of intangibles	(12,782)	(23,689)	(13,808)
Asset impairment charges	(521,441)	0	0
Interest expense, net	(819)	(720)	(250)
Non-operating pension cost	(221)	(243)	(153)
Income (loss) before taxes	$ (513,908)	$ (9,750)	$ 1,360

Disposal Group, Including Discontinued Operation, Non-Operating Pension Cost

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Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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