Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Jul. 31, 2018	[1]	Apr. 30, 2018	[1]	Jan. 31, 2018	[1]	Oct. 31, 2017	[1]	Jul. 31, 2017	[1]	Apr. 30, 2017	[1]	Jan. 31, 2017	[1]	Oct. 31, 2016	[1]	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Income From Continuing Operations Before Taxes [Abstract]
Income before income tax expense	$ 132,729		$ 171,216		$ 144,438		$ 114,128		$ 106,379		$ 131,088		$ 100,099		$ 102,534		$ 562,511	$ 440,100	$ 395,865
UNITED STATES
Income From Continuing Operations Before Taxes [Abstract]
U.S.																	501,961	385,526	339,013
International [Member]
Income From Continuing Operations Before Taxes [Abstract]
International																	$ 60,550	$ 54,574	$ 56,852

[1] Earnings per share were computed independently for each of the periods presented; therefore, the sum of the earnings per share amounts for the quarters may not equal the total for the year.