Condensed Financial Information of Registrant Balance Sheets (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Current assets
Cash and cash equivalents		$ 139,188	$ 100,508	$ 48,999	$ 85,057
Prepaid expenses and other current assets		27,139	25,135
Total current assets		294,858	271,479
Deferred charges and other assets, net		11,933	11,236
Total assets		692,970	685,508
Current liabilities
Accrued expenses		103,855	107,745
Total current liabilities		289,922	278,512
Long-term debt		92,500	100,000
Partners' capital		301,493	289,886	273,245	259,281
Total liabilities and partners' capital		692,970	685,508
STAR GAS PARTNERS, L.P.
Current assets
Cash and cash equivalents		324	324	$ 324	$ 324
Prepaid expenses and other current assets		199	210
Total current assets		523	534
Investment in subsidiaries	[1]	301,368	289,744
Deferred charges and other assets, net		0	0
Total assets		301,891	290,278
Current liabilities
Accrued expenses		398	392
Total current liabilities		398	392
Long-term debt		0	0
Partners' capital		301,493	289,886
Total liabilities and partners' capital		$ 301,891	$ 290,278

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