Disaggregation of Revenue - Schedule of Revenue Disaggregation for Customer Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 27, 2025	Sep. 28, 2024	Sep. 30, 2023
Disaggregation Of Revenue [Line Items]
Total revenues	$ 1,432,518	$ 1,327,172	$ 1,429,194
Retail [Member] | Residential [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	766,528	706,768	771,783
Retail [Member] | Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	404,181	372,828	393,482
Retail [Member] | Industrial [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	120,579	120,985	130,656
Retail [Member] | Government [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	67,976	61,396	65,489
Retail [Member] | Agricultural [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	33,398	36,568	40,971
Wholesale [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 39,856	$ 28,627	$ 26,813