Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 03, 2020	Mar. 29, 2019	Apr. 03, 2020	Mar. 29, 2019
Earnings Per Share [Abstract]
Fair Value Adjustment of Warrants	$ (8,647)	$ 1,607	$ (4,560)	$ (3,862)
Numerator:
Net loss	(10,226)	(46,204)	(38,588)	(69,600)
Warrant liability gain	(8,647)	0	(4,560)	(3,862)
Net loss attributable to common stockholders	$ (18,873)	$ (46,204)	$ (43,148)	$ (73,462)
Denominator:
Weighted average common shares outstanding-basic	66,522,000	65,531,000	66,375,000	65,404,000
Dilutive effect of options and warrants (in shares)	562,567	0	545,578	206,104
Weighted average common shares outstanding-diluted	67,085,000	65,531,000	66,921,000	65,610,000
Loss per share-basic:
Loss per share - basic	$ (0.15)	$ (0.71)	$ (0.58)	$ (1.06)
Loss per share-diluted:
Loss per share - diluted	$ (0.28)	$ (0.71)	$ (0.64)	$ (1.12)
Number of antidilutive shares of common stock excluded from the calculation (in shares)	1,009,830	425,202	886,671	154,377