Condensed Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2014		Mar. 31, 2013
Sales:
Product	$ 839,953		$ 732,949		$ 1,303,340		$ 1,187,419
Installations and service	52,288		52,190		109,511		114,245
Total sales	892,241		785,139		1,412,851		1,301,664
Cost and expenses:
Cost of product	639,564		571,790		998,141		928,403
Cost of installations and service	53,032		51,338		106,475		108,559
(Increase) decrease in the fair value of derivative instruments	4,105		(3,447)		(1,353)		4,518
Delivery and branch expenses	92,428		83,322		160,828		151,709
Depreciation and amortization expenses	4,917		4,321		9,276		8,679
General and administrative expenses	6,449		4,761		11,855		9,252
Finance charge income	(2,207)		(2,174)		(3,211)		(3,262)
Operating income	93,953		75,228		130,840		93,806
Interest expense, net	(4,274)		(4,014)		(7,897)		(7,431)
Amortization of debt issuance costs	(390)		(418)		(811)		(910)
Income before income taxes	89,289		70,796		122,132		85,465
Income tax expense	37,073		29,117		50,628		34,034
Net income	52,216		41,679		71,504		51,431
General Partner's interest in net income	294		225		403		278
Limited Partners' interest in net income	$ 51,922		$ 41,454		$ 71,101		$ 51,153
Basic and diluted income per Limited Partner Unit	$ 0.75	[1]	$ 0.58	[1]	$ 1.03	[1]	$ 0.72	[1]
Weighted average number of Limited Partner units outstanding:
Basic and Diluted	57,468		59,837		57,490		60,192

[1] See Note 14 Earnings Per Limited Partner Unit.