Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Income Statement [Abstract]
Net sales	$ 1,290,576	$ 1,971,560	$ 3,046,552	$ 4,203,228
Cost of products sold	1,148,980	1,701,232	2,697,700	3,599,715
Gross profit	141,596	270,328	348,852	603,513
Selling, general and administrative expenses	85,069	117,088	187,762	251,351
Amortization of intangible assets	12,526	13,796	25,117	27,354
Acquisition-related costs	42,059		99,148
Interest income	1,675	401	2,897	782
Interest expense	859	1,354	1,735	2,766
Other income (expense), net	(885)	2,574	(4,597)	5,332
Income before income taxes	1,873	141,065	33,390	328,156
Income taxes	7,290	61,313	24,854	119,998
Net and comprehensive income (loss)	$ (5,417)	$ 79,752	$ 8,536	$ 208,158
Weighted-average common shares outstanding:
Basic	52,806,981	52,694,680	52,766,739	52,653,303
Diluted	52,867,687	52,861,140	52,883,645	52,839,752
Earnings (loss) per common share:
Basic	$ (0.10)	$ 1.51	$ 0.16	$ 3.95
Diluted	(0.10)	1.51	0.16	3.94
Regular dividends declared and paid per common share	$ 0.39	$ 0.37	$ 0.78	$ 0.74