Consolidating Condensed Financial Information of Guarantor Subsidiaries - Consolidating Condensed Balance Sheet (Detail) - USD ($) $ in Thousands	Sep. 24, 2016	Sep. 26, 2015	Sep. 27, 2014	Sep. 28, 2013
ASSETS
Cash and cash equivalents	$ 92,982	$ 47,584	$ 78,676	$ 15,156
Restricted cash	10,910	13,157
Accounts receivable, net	201,151	207,402
Inventories	362,004	335,946
Prepaid expenses and other assets	47,759	49,731
Total current assets	714,806	653,820
Land, buildings, improvements and equipment, net	158,224	162,809
Goodwill	231,385	209,089	208,233	205,756
Other long term assets	107,778	105,879
Intercompany receivable	0	0
Investment in subsidiaries	0	0
Total	1,212,193	1,131,597	1,148,727
LIABILITIES AND EQUITY
Accounts payable	102,413	88,889
Accrued expenses and other liabilities	99,343	87,724
Current portion of long-term debt	463	291
Total current liabilities	202,219	176,904
Long-term debt	394,806	396,691
Intercompany payable	0	0
Losses in excess of investment in subsidiaries	0	0
Other long-term obligations	60,581	51,622
Shareholders’ equity attributable to Central Garden & Pet	553,014	505,286
Noncontrolling interest	1,573	1,094
Total equity	554,587	506,380	486,453	470,024
Total	1,212,193	1,131,597
Eliminations [Member]
ASSETS
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other assets	0	0
Total current assets	0	0
Land, buildings, improvements and equipment, net	0	0
Goodwill	0	0
Other long term assets	(11,458)	(6,100)
Intercompany receivable	(600,152)	(470,080)
Investment in subsidiaries	(1,176,990)	(1,075,028)
Total	(1,788,600)	(1,551,208)
LIABILITIES AND EQUITY
Accounts payable	0	0
Accrued expenses and other liabilities	0	0
Current portion of long-term debt	0	0
Total current liabilities	0	0
Long-term debt	0	0
Intercompany payable	(600,152)	(470,080)
Losses in excess of investment in subsidiaries	(16,126)	(11,867)
Other long-term obligations	(11,458)	(6,100)
Shareholders’ equity attributable to Central Garden & Pet	(1,160,864)	(1,063,161)
Noncontrolling interest	0	0
Total equity	(1,160,864)	(1,063,161)
Total	(1,788,600)	(1,551,208)
Parent [Member]
ASSETS
Cash and cash equivalents	82,158	36,280	63,471	5,438
Restricted cash	10,910	13,157
Accounts receivable, net	59,617	46,326
Inventories	113,317	86,109
Prepaid expenses and other assets	20,978	22,926
Total current assets	286,980	204,798
Land, buildings, improvements and equipment, net	41,083	51,409
Goodwill	15,058	0
Other long term assets	30,555	25,881
Intercompany receivable	32,778	32,695
Investment in subsidiaries	1,176,990	1,075,028
Total	1,583,444	1,389,811
LIABILITIES AND EQUITY
Accounts payable	34,096	20,506
Accrued expenses and other liabilities	47,862	38,723
Current portion of long-term debt	88	261
Total current liabilities	82,046	59,490
Long-term debt	394,364	396,626
Intercompany payable	553,964	426,639
Losses in excess of investment in subsidiaries	0	0
Other long-term obligations	56	1,770
Shareholders’ equity attributable to Central Garden & Pet	553,014	505,286
Noncontrolling interest	0	0
Total equity	553,014	505,286
Total	1,583,444	1,389,811
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	9,695	10,022	12,806	7,003
Restricted cash	0	0
Accounts receivable, net	5,156	6,775
Inventories	11,752	11,690
Prepaid expenses and other assets	817	848
Total current assets	27,420	29,335
Land, buildings, improvements and equipment, net	3,897	3,663
Goodwill	0	0
Other long term assets	2,980	3,662
Intercompany receivable	0	0
Investment in subsidiaries	0	0
Total	34,297	36,660
LIABILITIES AND EQUITY
Accounts payable	3,953	2,543
Accrued expenses and other liabilities	1,410	1,789
Current portion of long-term debt	0	0
Total current liabilities	5,363	4,332
Long-term debt	0	0
Intercompany payable	46,188	43,441
Losses in excess of investment in subsidiaries	0	0
Other long-term obligations	0	0
Shareholders’ equity attributable to Central Garden & Pet	(18,827)	(12,207)
Noncontrolling interest	1,573	1,094
Total equity	(17,254)	(11,113)
Total	34,297	36,660
Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	1,129	1,282	$ 2,399	$ 2,715
Restricted cash	0	0
Accounts receivable, net	136,378	154,301
Inventories	236,935	238,147
Prepaid expenses and other assets	25,964	25,957
Total current assets	400,406	419,687
Land, buildings, improvements and equipment, net	113,244	107,737
Goodwill	216,327	209,089
Other long term assets	85,701	82,436
Intercompany receivable	567,374	437,385
Investment in subsidiaries	0	0
Total	1,383,052	1,256,334
LIABILITIES AND EQUITY
Accounts payable	64,364	65,840
Accrued expenses and other liabilities	50,071	47,212
Current portion of long-term debt	375	30
Total current liabilities	114,810	113,082
Long-term debt	442	65
Intercompany payable	0	0
Losses in excess of investment in subsidiaries	16,126	11,867
Other long-term obligations	71,983	55,952
Shareholders’ equity attributable to Central Garden & Pet	1,179,691	1,075,368
Noncontrolling interest	0	0
Total equity	1,179,691	1,075,368
Total	$ 1,383,052	$ 1,256,334