CONSOLIDATED STATEMENT OF STOCKHOLDERS' DEFICIT - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated Deficit [Member]	Total
Balance at beginning at Sep. 24, 2016	$ 1	$ 614	$ 33,105	$ (329,791)	$ (296,071)
Balance at beginning (in shares) at Sep. 24, 2016	11,801,369
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustments			18,697		18,697
Actuarial gains on pension plan			1,343		1,343
Shares issued in Merger	$ 1	326,237			326,238
Shares issued in Merger (in shares)	8,412,097
Earnout liability related to Merger		(9,575)			(9,575)
Sale of common stock		1,645			1,645
Sale of common stock (in shares)	164,536
Stock-based compensation expense		4,508			4,508
Stock-based compensation expense (in shares)	24,600
Net loss				(49,114)	(49,114)
Balance at ending at Sep. 30, 2017	$ 2	323,429	53,145	(378,905)	$ (2,329)
Balance at ending (in shares) at Sep. 30, 2017	20,402,602				20,402,602
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustments			273		$ 273
Actuarial gains on pension plan			5,209		5,209
Change in fair value of hedging instrument			261		261
Reclassification of gain on hedging instrument to comprehensive income			(308)		(308)
Shares issued on exercise of warrants		1			1
Shares issued on exercise of warrants (in shares)	50
Shares issued upon net settlement of RSUs and RSAs		(1,043)			(1,043)
Shares issued upon net settlement of RSUs and RSAs (in shares)	457,939
Reclassification of RSUs from derivative liability due to stockholder approval of Second Incentive Plan		2,848			2,848
Reclassification of RSUs to derivative liability due to modification		(1,482)			(1,482)
Stock-based compensation expense		4,699			4,699
Net loss				(20,596)	(20,596)
Balance at ending at Sep. 30, 2018	$ 2	$ 328,452	$ 58,580	$ (399,501)	$ (12,467)
Balance at ending (in shares) at Sep. 30, 2018	20,860,591				20,860,591