Segment Information Segment Income or Loss Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 26, 2020	Jun. 28, 2019	Jun. 26, 2020	Jun. 28, 2019
Segment Reporting Information [Line Items]
Operating income (loss)	$ (9,554)	$ (7,764)	$ (27,603)	$ (16,172)
Unallocated Corporate Expenses	(47,327)	(51,692)	(102,114)	(101,949)
Stock-based compensation	(3,548)	(2,510)	(9,807)	(4,623)
Amortization of intangibles	(807)	(2,079)	(2,462)	(4,162)
Nonoperating Income (Expense)	(4,269)	(3,384)	(7,445)	(6,601)
Loss before income taxes	(13,823)	(11,148)	(35,048)	(22,773)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	(5,115)	(2,807)	(14,647)	(6,661)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Unallocated Corporate Expenses	$ (84)	$ (368)	$ (687)	$ (726)

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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