Condensed Financial Information of Registrant Statements of Cash Flows (Detail) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Cash flows provided by (used in) financing activities:
Distributions		$ (21,298)	$ (19,850)	$ (19,313)
Redemption of debt		(125,000)
Unit repurchase		(691)	(1,663)	(15,217)
Net increase (decrease) in cash		51,509	(36,058)	(23,034)
Cash and equivalents at beginning of period		48,999	85,057	108,091
Cash and equivalents at end of period		100,508	48,999	85,057
STAR GAS PARTNERS, L.P.
Cash flows provided by (used in) operating activities:
Net cash provided by operating activities (a)	[1]	152,537	21,513	34,537
Cash flows provided by (used in) investing activities:
Net cash provided by (used in) investing activities		0	0	0
Cash flows provided by (used in) financing activities:
Distributions		(21,298)	(19,850)	(19,313)
Redemption of debt		(130,548)
Unit repurchase		(691)	(1,663)	(15,217)
Net cash used in financing activities		(152,537)	(21,513)	(34,530)
Net increase (decrease) in cash				7
Cash and equivalents at beginning of period		324	324	317
Cash and equivalents at end of period		$ 324	$ 324	$ 324

[1] Includes distributions from subsidiaries $ 152,537 $ 21,513 $ 34,530