Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2018	Oct. 31, 2017
Income Statement [Abstract]
Net sales	$ 1,755,976	$ 2,231,668
Cost of products sold	1,548,720	1,898,483
Gross profit	207,256	333,185
Selling, general and administrative expenses	102,693	134,263
Amortization of intangible assets	12,591	13,558
Acquisition-related costs	57,089
Interest income	1,222	381
Interest expense	876	1,412
Other income (expense), net	(3,712)	2,758
Income before income taxes	31,517	187,091
Income taxes	17,564	58,685
Net income and comprehensive income	$ 13,953	$ 128,406
Weighted-average common shares outstanding:
Basic	52,726,496	52,611,926
Diluted	52,899,603	52,818,363
Earnings per common share:
Basic	$ 0.26	$ 2.44
Diluted	0.26	2.43
Regular dividends declared per common share	$ 0.39	$ 0.37