Income Taxes (Details Textuals) - USD ($) $ in Thousands			3 Months Ended		12 Months Ended
	Jul. 31, 2018	Dec. 31, 2017	Jul. 31, 2018	Jan. 31, 2018	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
New Accounting Pronouncement, Early Adoption [Line Items]
Foreign Earnings Repatriated					$ 93,900
Tax Credit Carryforward, Amount	$ 3,800		$ 3,800		3,800	$ 5,500
Effective Income Tax Rate Reconciliation, Tax Credit, Percent	50.00%
Other Tax Expense Benefit Transition Tax Net of Foreign Tax Credit			12,400	$ 10,600
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			4,300	$ 600
Valuation allowance	$ 4,592		4,592		4,592	6,455
Unrecognized tax benefits that would impact effective tax rate	16,000		16,000		16,000	13,000
Interest and penalties related to income tax	$ 6,000		6,000		$ 6,000	$ 5,300	$ 4,900
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%			26.90%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Percent					25.70%	10.40%	31.70%
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense					$ 21,300	$ 107,600	$ 14,700
Undistributed Earnings of Foreign Subsidiaries	$ 160,000		$ 160,000		$ 160,000