Basis of Presentation - Additional Information (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2018 USD ($) wk	Jun. 24, 2017 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Limited partner interest in the Operating Partnership (in hundredths)	100.00%
Minimum number of weeks in the fiscal year reporting calendar	52
Maximum number of weeks in the fiscal year reporting calendar	53
Minimum number of weeks in a fiscal quarter	13
Maximum number of weeks in a fiscal quarter	14
Cash paid to taxing authorities on employee’s’ behalf for withheld shares | $	$ 847	$ 736