Reportable Segments - Summary of Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 30, 2025	Mar. 31, 2024	Mar. 30, 2025	Mar. 31, 2024	Sep. 29, 2024
Segment Reporting Information [Line Items]
Revenue	$ 1,322,113	$ 1,251,616	$ 2,742,674	$ 2,479,883
Income from operations	39,603	117,683	62,129	228,764
Total Assets	4,184,304		4,184,304		$ 4,192,676
Operating segments | GSG
Segment Reporting Information [Line Items]
Revenue	661,424	597,127	1,413,206	1,172,168
Income from operations	72,104	64,007	155,386	127,134
Total Assets	866,729		866,729		658,493
Operating segments | CIG
Segment Reporting Information [Line Items]
Revenue	678,838	671,155	1,367,073	1,340,262
Income from operations	76,770	75,955	154,447	147,356
Total Assets	990,914		990,914		1,059,915
Elimination of inter-segment revenue
Segment Reporting Information [Line Items]
Revenue	(18,149)	(16,666)	(37,605)	(32,547)
Corporate
Segment Reporting Information [Line Items]
Income from operations	(109,271)	$ (22,279)	(247,704)	$ (45,726)
Total Assets	$ 2,326,661		$ 2,326,661		$ 2,474,268