Disaggregation of Revenue - Schedule of Revenue Disaggregation for Customer Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 24, 2022	Sep. 25, 2021	Sep. 26, 2020
Disaggregation Of Revenue [Line Items]
Total revenues	$ 1,501,465	$ 1,288,755	$ 1,107,897
Retail [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	798,784	703,263	654,265
Retail [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	435,015	353,365	283,021
Retail [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	136,257	111,723	92,969
Retail [Member] | Agricultural [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	45,259	37,873	33,718
Retail [Member] | Government [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	66,035	51,917	43,441
Wholesale [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 20,115	$ 30,614	$ 483