CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Sales:
Total sales		$ 699,582	$ 684,031	$ 1,234,609	$ 1,120,865
Cost and expenses:
(Increase) decrease in the fair value of derivative instruments	[1]	(13,401)	11,609	17,638	209
Delivery and branch expenses		110,684	106,605	213,357	197,809
Depreciation and amortization expenses		7,858	7,703	15,603	15,444
General and administrative expenses		9,849	6,221	17,664	12,872
Finance charge income		(1,443)	(1,532)	(2,294)	(2,295)
Operating income		105,002	85,473	111,065	116,539
Interest expense, net		(3,194)	(2,383)	(5,710)	(4,470)
Amortization of debt issuance costs		(244)	(307)	(503)	(616)
Income before income taxes		101,564	82,783	104,852	111,453
Income tax expense		29,239	28,005	30,212	26,493
Net income		72,325	54,778	74,640	84,960
General Partner’s interest in net income		454	319	469	494
Limited Partners’ interest in net income		$ 71,871	$ 54,459	$ 74,171	$ 84,466
Basic and diluted income per Limited Partner Unit :	[2]	$ 1.15	$ 0.81	$ 1.19	$ 1.26
Weighted average number of Limited Partner units outstanding:
Basic and Diluted		51,427	55,642	52,174	55,766
Product
Sales:
Total sales		$ 637,400	$ 622,962	$ 1,096,107	$ 989,696
Installations and services
Sales:
Total sales		62,182	61,069	138,502	131,169
Cost of product
Cost and expenses:
Cost and expenses		415,639	403,293	721,865	646,073
Cost of installations and services
Cost and expenses:
Cost and expenses		$ 65,394	$ 64,659	$ 139,711	$ 134,214

[1] Represents the change in value of unrealized open positions and expired options.

[2] See Note 15 - Earnings Per Limited Partner Unit.