Stockholder's Equity (Details Textuals 1) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			12 Months Ended			68 Months Ended
	Oct. 31, 2019	Apr. 30, 2019	Jan. 31, 2018	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2020	Sep. 22, 2011
Targeted or Tracking Stock, Stock [Line Items]
Document Period End Date				Jul. 31, 2020
Stock Repurchase [Abstract]
Stock repurchase price per share (in dollars per share)					$ 47.81
Company repurchased common stock					$ 365,000
Payments for Employee Stock-Based Tax Withholdings	$ 101,348	$ 45,565	$ 0	$ 103,451	$ 46,888	$ 1,115
Stock Repurchase Program 2011 [Member]
Stock Repurchase [Abstract]
Additional common stock authorized for repurchase (in shares)								80,000,000
Common stock authorized for repurchase (in shares)								196,000,000
Company repurchased common stock (in shares)					7,635,596		114,549,198
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased				81,450,802			81,450,802
Settlement with Taxing Authority [Member]
Stock Repurchase [Abstract]
Payments for Employee Stock-Based Tax Withholdings				$ 101,300	$ 45,600	$ 0