Segment Information - Financial Information Relating to Company's Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 28, 2026	Mar. 29, 2025	Mar. 28, 2026	Mar. 29, 2025	Sep. 27, 2025
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Cost of goods sold	$ 606,588	$ 560,454	$ 1,033,353	$ 1,021,191
Selling, general and administrative expenses	185,628	179,759	359,703	347,466
Operating income	113,936	93,324	130,469	121,316
Interest income	4,984	5,152	11,728	11,892
Other expense	(351)	744	(169)	(973)
Income before income taxes and noncontrolling interest	104,501	84,710	113,449	103,255
Depreciation and amortization:
Depreciation and amortization	20,684	20,646	41,344	42,580
Assets:
Total assets	3,745,528	3,629,617	3,745,528	3,629,617	$ 3,625,643
Goodwill (included in corporate assets above):
Goodwill	554,692	554,692	554,692	554,692	554,692
Operating Segments
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	906,152	833,537	1,523,525	1,489,973
Operating income	143,790	119,345	183,911	173,025
Depreciation and amortization:
Depreciation and amortization	20,453	19,941	40,864	41,152
Assets:
Total assets	2,456,278	2,541,579	2,456,278	2,541,579	2,173,210
Operating Segments | Pet
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	476,842	453,710	892,654	881,172
Cost of goods sold	296,931	290,674	565,286	569,569
Selling, general and administrative expenses	102,089	102,422	199,746	199,732
Operating income	77,822	60,614	127,622	111,871
Depreciation and amortization:
Depreciation and amortization	10,462	9,498	20,599	19,578
Assets:
Total assets	992,989	1,025,398	992,989	1,025,398	941,122
Goodwill (included in corporate assets above):
Goodwill	285,323	285,323	285,323	285,323	285,323
Operating Segments | Garden
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Net sales	429,310	379,827	630,871	608,801
Cost of goods sold	309,657	269,780	468,067	451,622
Selling, general and administrative expenses	53,685	51,316	106,515	96,025
Operating income	65,968	58,731	56,289	61,154
Depreciation and amortization:
Depreciation and amortization	9,991	10,443	20,265	21,574
Assets:
Total assets	1,463,289	1,516,181	1,463,289	1,516,181	1,232,088
Goodwill (included in corporate assets above):
Goodwill	269,369	269,369	269,369	269,369	269,369
Unallocated corporate items
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Unallocated corporate items	(29,854)	(26,021)	(53,442)	(51,709)
Interest expense	(14,068)	(14,510)	(28,579)	(28,980)
Interest income	4,984	5,152	11,728	11,892
Depreciation and amortization:
Depreciation and amortization	231	705	480	1,428
Assets:
Total assets	1,289,250	1,088,038	1,289,250	1,088,038	$ 1,452,433
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Other expense	$ (351)	$ 744	$ (169)	$ (973)