Debt - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Sep. 30, 2017
Debt Instrument [Line Items]
Loss on debt extinguishment	$ 0	$ (10,142)
Interest expense	1,500	$ 2,700
Senior Term Loan | Senior Credit Facility
Debt Instrument [Line Items]
Long-term line of credit	$ 152,000		$ 154,000
Stated interest rate (as a percent)	3.10%		2.80%
Weighted average effective interest rate (as a percent)	3.60%		4.50%
Revolving Credit Facility | Credit Facility | Senior Revolving Credit Facility
Debt Instrument [Line Items]
Long-term line of credit	$ 0
Letters of Credit | Credit Facility | Senior Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit, amount outstanding	7,700
Remaining borrowing capacity	$ 67,300