Impairment and other charges, net Restructuring cost (Details) - USD ($) $ in Thousands	4 Months Ended
	Jan. 19, 2020	Jan. 20, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,045	$ 5,840
Employee Severance and Related Costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	1,045	4,506
Strategic Alternative Evaluation
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0	$ 1,334	[1]

[1] Strategic Alternative Evaluation costs primarily relate to third party advisory services.