Condensed Financial Information of Registrant (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statements of Operations [Abstract]
Revenues	$ 174,046	$ 232,476	$ 629,592	$ 461,474	$ 153,172	$ 246,772	$ 731,865	$ 459,501	$ 1,497,588	$ 1,591,310	$ 1,212,776
General and administrative expenses									18,689	20,709	21,397
Operating loss	(7,543)	(20,051)	72,879	8,581	(41,297)	(28,266)	87,959	43,651	53,866	62,047	58,584
Interest expense									(14,110)	(15,710)	(14,326)
Gain (loss) on redemption of debt										(1,700)	(1,132)
Income (loss) before income taxes	(10,457)	(22,434)	69,873	5,583	(43,867)	(30,784)	84,149	37,569	42,565	47,067	43,952
Net income	(5,635)	(11,789)	40,482	2,931	(26,698)	(18,197)	48,681	20,558	25,989	24,344	28,320
STAR GAS PARTNERS, L.P. [Member]
Consolidated Statements of Operations [Abstract]
Revenues
General and administrative expenses									2,019	2,026	2,231
Operating loss									(2,019)	(2,026)	(2,231)
Interest expense									(11,188)	(11,638)	(10,299)
Amortization of debt issuance costs									(330)	(501)	(336)
Gain (loss) on redemption of debt										(1,700)	(1,132)
Income (loss) before income taxes									(13,537)	(15,865)	(13,998)
Equity income of Star Petro Inc. and subs									39,526	40,209	42,426
Net income									$ 25,989	$ 24,344	$ 28,428