Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Common Stock Including Additional Paid in Capital	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders’ Equity	$ 1,098,600
Balances attributable to Parent at Jul. 31, 2017		$ 23		$ 453,349	$ (100,676)	$ 745,370
Stockholders' Equity Attributable to Noncontrolling Interest at Jul. 31, 2017							$ 534
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	417,867					417,867
Net Income (Loss), Attributable to Noncontrolling Interest	140						140
Net income	418,007
Currency translation adjustment	(7,252)				(7,252)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(235)						(235)
Exercise of stock options, net of repurchased shares	43,344			44,459		(1,115)
Employee stock-based compensation and related tax benefit	23,221			23,197		24
Shares issued for Employee Stock Purchase Plan	5,853			5,853
Stockholders' Equity Attributable to Noncontrolling Interest at Jul. 31, 2018							0
Balances attributable to Parent at Jul. 31, 2018		$ 23		526,858	(107,928)	1,162,146
Balances (in shares) at Jul. 31, 2017		230,488,296
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, net of repurchased shares (in shares)		3,225,377
Shares issued for Employee Stock Purchase Plan (in shares)		185,168
Balances (in shares) at Jul. 31, 2018		233,898,841
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders’ Equity	1,581,099
Net income	591,693			0	0	591,693
Net Income (Loss), Attributable to Noncontrolling Interest	0
Net income	591,693
Currency translation adjustment	(24,601)				(24,601)
Noncontrolling Interest, Decrease from Deconsolidation	(439)						(439)
Exercise of stock options, net of repurchased shares	(12,487)			32,500		(44,987)
Employee stock-based compensation and related tax benefit	23,445			23,445
Shares issued for Employee Stock Purchase Plan	7,183			7,183
Shares repurchased	(364,997)			(17,427)		(347,570)
Stockholders' Equity Attributable to Noncontrolling Interest at Jul. 31, 2019							0
Balances attributable to Parent at Jul. 31, 2019		$ 23		572,559	(132,529)	1,338,328
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, net of repurchased shares (in shares)		3,349,980
Shares issued for Employee Stock Purchase Plan (in shares)		177,043
Shares repurchased (in shares)		(7,635,596)
Balances (in shares) at Jul. 31, 2019		229,790,268
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders’ Equity	1,778,381
Net income	699,907					699,907
Net Income (Loss), Attributable to Noncontrolling Interest	0
Net income	699,907
Currency translation adjustment	11,441				11,441	0
Exercise of stock options, net of repurchased shares	(31,811)			68,570		(100,382)
Employee stock-based compensation and related tax benefit	23,322			23,322		0
Shares issued for Employee Stock Purchase Plan	8,276			8,276		0
Stockholders' Equity Attributable to Noncontrolling Interest at Jul. 31, 2020							$ 0
Balances attributable to Parent at Jul. 31, 2020		$ 24		$ 672,727	$ (121,088)	$ 1,937,853
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, net of repurchased shares (in shares)		5,401,963	1,000
Shares issued for Employee Stock Purchase Plan (in shares)		123,106
Balances (in shares) at Jul. 31, 2020		235,315,337
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders’ Equity	$ 2,489,516