CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 25, 2021	Dec. 26, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 21,298	$ 37,977
Other comprehensive income:
Amortization of net actuarial losses and prior service credits into earnings	294	593
Other comprehensive income	294	593
Total comprehensive income	$ 21,592	$ 38,570