CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 26, 2020	Dec. 28, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 37,977	$ 40,163
Amortization of net actuarial losses and prior service credits into earnings	593	541
Other comprehensive income	593	541
Total comprehensive income	$ 38,570	$ 40,704