Segment Information - Financial Information Relating to Company's Business Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Sep. 26, 2015
Net sales:
Net sales	$ 359,812	$ 307,320
Income (loss) from operations:
Income from operations	8,773	1,138
Interest expense - net	(22,123)	(10,432)
Other expense	(473)	(368)
Income tax benefit	(5,200)	(3,969)
Loss including noncontrolling interest	(8,623)	(5,693)
Net income (loss) attributable to noncontrolling interest	(21)	4
Net loss attributable to Central Garden & Pet Company	(8,602)	(5,697)
Depreciation and amortization:
Depreciation and amortization	9,032	8,464
Assets:
Total assets	1,211,209	1,184,307	$ 1,131,597
Goodwill (included in corporate assets above):
Goodwill	209,089	208,233	209,089
Operating Segments [Member] | Pet Segment [Member]
Net sales:
Net sales	248,662	199,320
Income (loss) from operations:
Income from operations	26,195	20,575
Depreciation and amortization:
Depreciation and amortization	4,464	3,941
Assets:
Total assets	540,218	425,528	465,171
Goodwill (included in corporate assets above):
Goodwill	209,089	208,233	209,089
Operating Segments [Member] | Garden Segment [Member]
Net sales:
Net sales	111,150	108,000
Income (loss) from operations:
Income from operations	(3,254)	(3,535)
Depreciation and amortization:
Depreciation and amortization	1,685	1,566
Assets:
Total assets	342,811	350,835	310,981
Corporate [Member]
Income (loss) from operations:
Income from operations	(14,168)	(15,902)
Depreciation and amortization:
Depreciation and amortization	2,883	2,957
Assets:
Total assets	$ 328,180	$ 407,944	$ 355,445