Income Taxes - Provision for Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Current:
Federal	$ 33,775	$ 17,048	$ 5,728
State	5,063	2,728	2,319
Foreign	(5)	169	91
Total	38,833	19,945	8,138
Deferred:
Federal	(6,019)	4,278	(3,676)
State	(582)	2,380	(1,162)
Foreign	(14)	1	5
Total	(6,615)	6,659	(4,833)
Total	$ 32,218	$ 26,604	$ 3,305