Consolidating Condensed Balance Sheet Based on Company's Understanding of SEC's Interpretation (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 27, 2014	Sep. 27, 2014	Dec. 28, 2013	Sep. 28, 2013
ASSETS
Cash and cash equivalents	$ 79,588	$ 78,676	$ 16,711	$ 15,156
Restricted cash	19,690	14,283	0
Short term investments	9,992	9,990	14,220
Accounts receivable, net	142,877	193,729	143,105
Inventories	399,936	326,386	427,439
Prepaid expenses and other	64,280	48,488	69,100
Total current assets	716,363	671,552	670,575
Land, buildings, improvements and equipment, net	163,546	166,849	187,138
Goodwill	208,233	208,233	205,756
Other long term assets	100,821	102,093	92,499
Intercompany receivable	0	0	0
Investment in subsidiaries	0	0	0
Total	1,188,963	1,148,727	1,155,968
LIABILITIES AND EQUITY
Accounts payable	128,485	88,428	120,548
Accrued expenses	93,208	84,379	88,512
Current portion of long term debt	50,289	291	73
Total current liabilities	271,982	173,098	209,133
Long-term debt	399,913	449,948	449,465
Intercompany payable	0	0
Losses in excess of investment in subsidiaries	0	0	0
Other long-term obligations	42,212	39,228	38,867
Central Garden & Pet shareholders' equity	474,802	484,723	457,894
Noncontrolling interest	54	1,730	609
Total equity	474,856	486,453	458,503	470,024
Total	1,188,963	1,148,727	1,155,968
Parent [Member]
ASSETS
Cash and cash equivalents	71,579	63,471	8,862	5,438
Restricted cash	19,690	14,283	0
Short term investments	9,992	9,990	14,220
Accounts receivable, net	38,580	41,235	36,241
Inventories	101,870	79,199	110,337
Prepaid expenses and other	33,095	26,092	33,814
Total current assets	274,806	234,270	203,474
Land, buildings, improvements and equipment, net	59,829	63,059	74,595
Goodwill	0	0	0
Other long term assets	21,809	25,230	23,907
Intercompany receivable	37,337	16,906	15,840
Investment in subsidiaries	989,226	983,413	932,224
Total	1,383,007	1,322,878	1,250,040
LIABILITIES AND EQUITY
Accounts payable	39,847	28,937	43,748
Accrued expenses	47,888	34,151	43,137
Current portion of long term debt	50,259	261	39
Total current liabilities	137,994	63,349	86,924
Long-term debt	399,826	449,855	449,444
Intercompany payable	368,765	323,314	254,043
Losses in excess of investment in subsidiaries	0	0	0
Other long-term obligations	1,620	1,636	1,735
Central Garden & Pet shareholders' equity	474,802	484,724	457,894
Noncontrolling interest	0	0	0
Total equity	474,802	484,724	457,894
Total	1,383,007	1,322,878	1,250,040
Non-Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	5,505	12,806	4,280	7,003
Restricted cash	0	0	0
Short term investments	0	0	0
Accounts receivable, net	7,573	8,268	5,984
Inventories	22,481	15,210	26,567
Prepaid expenses and other	962	816	953
Total current assets	36,521	37,100	37,784
Land, buildings, improvements and equipment, net	3,607	3,649	2,395
Goodwill	0	0	0
Other long term assets	4,121	4,244	3,737
Intercompany receivable	0	0	0
Investment in subsidiaries	0	0	0
Total	44,249	44,993	43,916
LIABILITIES AND EQUITY
Accounts payable	10,077	3,542	7,152
Accrued expenses	1,751	1,868	1,483
Current portion of long term debt	0	0	0
Total current liabilities	11,828	5,410	8,635
Long-term debt	0	0	0
Intercompany payable	47,419	45,015	45,115
Losses in excess of investment in subsidiaries	0	0	0
Other long-term obligations	0	0	0
Central Garden & Pet shareholders' equity	(15,052)	(7,162)	(10,443)
Noncontrolling interest	54	1,730	609
Total equity	(14,998)	(5,432)	(9,834)
Total	44,249	44,993	43,916
Guarantor Subsidiaries [Member]
ASSETS
Cash and cash equivalents	2,504	2,399	3,569	2,715
Restricted cash	0	0	0
Short term investments	0	0	0
Accounts receivable, net	96,724	144,226	100,880
Inventories	275,585	231,977	290,535
Prepaid expenses and other	30,223	21,580	34,333
Total current assets	405,036	400,182	429,317
Land, buildings, improvements and equipment, net	100,110	100,141	110,148
Goodwill	208,233	208,233	205,756
Other long term assets	83,088	83,713	73,532
Intercompany receivable	378,847	351,423	283,318
Investment in subsidiaries	0	0	0
Total	1,175,314	1,143,692	1,102,071
LIABILITIES AND EQUITY
Accounts payable	78,561	55,949	69,648
Accrued expenses	43,569	48,360	43,892
Current portion of long term debt	30	30	34
Total current liabilities	122,160	104,339	113,574
Long-term debt	87	93	21
Intercompany payable	0	0
Losses in excess of investment in subsidiaries	14,900	7,594	9,399
Other long-term obligations	48,789	48,686	45,809
Central Garden & Pet shareholders' equity	989,378	982,980	933,268
Noncontrolling interest	0	0	0
Total equity	989,378	982,980	933,268
Total	1,175,314	1,143,692	1,102,071
Eliminations [Member]
ASSETS
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0	0
Short term investments	0	0	0
Accounts receivable, net	0	0	0
Inventories	0	0	0
Prepaid expenses and other	0	0	0
Total current assets	0	0	0
Land, buildings, improvements and equipment, net	0	0	0
Goodwill	0	0	0
Other long term assets	(8,197)	(11,094)	(8,677)
Intercompany receivable	(416,184)	(368,329)	(299,158)
Investment in subsidiaries	(989,226)	(983,413)	(932,224)
Total	(1,413,607)	(1,362,836)	(1,240,059)
LIABILITIES AND EQUITY
Accounts payable	0	0	0
Accrued expenses	0	0	0
Current portion of long term debt	0	0	0
Total current liabilities	0	0	0
Long-term debt	0	0	0
Intercompany payable	(416,184)	(368,329)	(299,158)
Losses in excess of investment in subsidiaries	(14,900)	(7,594)	(9,399)
Other long-term obligations	(8,197)	(11,094)	(8,677)
Central Garden & Pet shareholders' equity	(974,326)	(975,819)	(922,825)
Noncontrolling interest	0	0	0
Total equity	(974,326)	(975,819)	(922,825)
Total	$ (1,413,607)	$ (1,362,836)	$ (1,240,059)