CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 40,466,332	$ 38,169,265
Cost of goods sold	39,353,680	37,131,585
Gross profit	1,112,652	1,037,680
Operating expenses:
Distribution, selling, and administrative	558,522	520,547
Depreciation	64,907	55,854
Amortization	40,229	40,226
Employee severance, litigation, and other	30,021	21,066
Operating income	418,973	399,987
Other loss (income)	324	(123)
Interest expense, net	35,864	36,972
Loss on early retirement of debt	23,766	0
Income before income taxes	359,019	363,138
Income tax (benefit) expense	(502,834)	115,892
Net income	$ 861,853	$ 247,246
Earnings per share:
Basic (usd per share)	$ 3.95	$ 1.13
Diluted (usd per share)	$ 3.90	$ 1.11
Weighted average common shares outstanding:
Basic (shares)	218,323	218,661
Diluted (shares)	220,822	221,979
Cash dividends declared per share of common stock (usd per share)	$ 0.38	$ 0.365