Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Mar. 31, 2015		Mar. 31, 2014
Sales:
Product	$ 706,004		$ 839,953		$ 1,141,016		$ 1,303,340
Installations and services	56,305		52,288		120,510		109,511
Total sales	762,309		892,241		1,261,526		1,412,851
Cost and expenses:
Cost of product	462,815		639,564		772,064		998,141
Cost of installations and services	60,362		53,032		121,045		106,475
(Increase) decrease in the fair value of derivative instruments	(12,631)		4,105		(4,341)		(1,353)
Delivery and branch expenses	106,107		92,428		184,941		160,828
Depreciation and amortization expenses	6,217		4,917		12,375		9,276
General and administrative expenses	6,861		6,449		12,917		11,855
Finance charge income	(1,517)		(2,207)		(2,343)		(3,211)
Operating income	134,095		93,953		164,868		130,840
Interest expense, net	(3,816)		(4,274)		(7,276)		(7,897)
Amortization of debt issuance costs	(403)		(390)		(803)		(811)
Income before income taxes	129,876		89,289		156,789		122,132
Income tax expense	54,189		37,073		65,548		50,628
Net income	75,687		52,216		91,241		71,504
General Partner's interest in net income	428		294		516		403
Limited Partners' interest in net income	$ 75,259		$ 51,922		$ 90,725		$ 71,101
Basic and diluted income per Limited Partner Unit	$ 1.08	[1]	$ 0.75	[1]	$ 1.31	[1]	$ 1.03	[1]
Weighted average number of Limited Partner units outstanding:
Basic and Diluted	57,282		57,468		57,288		57,490

[1] See Note 13 Earnings Per Limited Partner Unit.