Condensed Consolidated Statements of Income and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Income Statement [Abstract]
Net sales	$ 1,971,560	$ 1,588,525	$ 4,203,228	$ 3,297,056
Cost of products sold	1,701,232	1,376,823	3,599,715	2,848,602
Gross profit	270,328	211,702	603,513	448,454
Selling, general and administrative expenses	117,088	96,969	251,351	199,279
Amortization of intangible assets	13,796	15,279	27,354	33,494
Interest income	401	177	782	330
Interest expense	1,354	2,486	2,766	5,046
Other income, net	2,574	1,220	5,332	3,200
Income before income taxes	141,065	98,365	328,156	214,165
Income taxes	61,313	33,583	119,998	70,638
Net income and comprehensive income	$ 79,752	$ 64,782	$ 208,158	$ 143,527
Weighted-average common shares outstanding:
Basic	52,694,680	52,582,134	52,653,303	52,543,050
Diluted	52,861,140	52,740,959	52,839,752	52,723,450
Earnings per common share:
Basic	$ 1.51	$ 1.23	$ 3.95	$ 2.73
Diluted	1.51	1.23	3.94	2.72
Regular dividends declared and paid per common share	$ 0.37	$ 0.33	$ 0.74	$ 0.66