Impairment and other charges, net Accrued severance (Details) - USD ($) $ in Thousands		4 Months Ended
		Jan. 20, 2019	Jan. 21, 2018	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		$ 5,840	$ 358
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		5,583		$ 5,309
Restructuring Costs	[1]	4,506	$ (456)
Payments for Restructuring		(4,200)
Employee Severance & Other [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		$ 4,474

[1] 2018 reflects a reduction in severance and related costs due to a change in the number of employees to be terminated in connection with our restructuring activities.