Disaggregation of Revenue - Schedule of Revenue Disaggregation for Customer Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 24, 2023	Jun. 25, 2022	Jun. 24, 2023	Jun. 25, 2022
Disaggregation Of Revenue [Line Items]
Total revenues	$ 278,628	$ 300,332	$ 1,202,599	$ 1,263,834
Retail [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	142,941	143,813	665,541	684,378
Retail [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	82,321	95,341	322,623	358,126
Retail [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	28,362	31,658	103,210	107,228
Retail [Member] | Agricultural [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	6,750	8,353	35,223	38,072
Retail [Member] | Government [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	12,039	13,295	56,870	57,560
Wholesale [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 6,215	$ 7,872	$ 19,132	$ 18,470