Condensed Financial Information of Registrant Balance Sheets (Detail) - USD ($) $ in Thousands		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Current assets
Cash and cash equivalents		$ 100,508	$ 48,999	$ 85,057	$ 108,091
Prepaid expenses and other current assets		25,135	23,943
Total current assets		309,311	296,465
Deferred charges and other assets, net		11,236	11,109
Total assets		707,032	685,107
Current liabilities
Accrued expenses		107,745	102,934
Total current liabilities		278,512	253,432
Long-term debt		100,000	124,572
Partners' capital		289,886	273,245	259,281	260,145
Total liabilities and partners' capital		707,032	685,107
STAR GAS PARTNERS, L.P.
Current assets
Cash and cash equivalents		324	324	$ 324	$ 317
Prepaid expenses and other current assets		210	203
Total current assets		534	527
Investment in subsidiaries	[1]	289,744	399,414
Deferred charges and other assets, net			2,003
Total assets		290,278	401,944
Current liabilities
Accrued expenses		392	4,127
Total current liabilities		392	4,127
Long-term debt			124,572
Partners' capital		289,886	273,245
Total liabilities and partners' capital		$ 290,278	$ 401,944

[1] Investments in Star Acquisitions, Inc. and subsidiaries are recorded in accordance with the equity method of accounting.