CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Sep. 26, 2015	Sep. 27, 2014	Sep. 28, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 84,352	$ 94,509	$ 78,798
Other comprehensive income:
Net unrealized (losses) gains on cash flow hedges	(1,159)	(518)	584
Reclassification of realized losses on cash flow hedges into earnings	1,388	1,406	2,465
Amortization of net actuarial losses and prior service credits into earnings and net change in funded status of benefit plans	(5,207)	560	10,705
Recognition in earnings of net actuarial loss for pension settlement	2,000	0	0
Other comprehensive (loss) income	(2,978)	1,448	13,754
Total comprehensive income	$ 81,374	$ 95,957	$ 92,552