Disaggregation of Revenue - Schedule of Revenue Disaggregation for Customer Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 25, 2022	Jun. 26, 2021	Jun. 25, 2022	Jun. 26, 2021
Disaggregation Of Revenue [Line Items]
Total revenues	$ 300,332	$ 238,085	$ 1,263,834	$ 1,080,514
Retail [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	143,813	120,186	684,378	605,827
Retail [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	95,341	76,215	358,126	284,541
Retail [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	31,658	25,270	107,228	86,512
Retail [Member] | Agricultural [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	8,353	6,181	38,072	30,890
Retail [Member] | Government [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	13,295	9,289	57,560	44,761
Wholesale [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 7,872	$ 944	$ 18,470	$ 27,983