Income Taxes (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jan. 31, 2018	Jul. 31, 2018	Jul. 31, 2017
Income Tax Contingency [Line Items]
Estimated net discrete tax benefit resulting from Tax Reform	$ 14,018,000
Unrecognized tax benefits	9,043,000		$ 8,681,000
Interest accrued relating to income taxes	147,000		95,000
Unrecognized tax benefits that would positively impact our effective tax rate, if recognized	8,351,000		7,727,000
Non-current income taxes payable
Income Tax Contingency [Line Items]
Unrecognized tax benefits	2,558,000		2,515,000
Included in the non-current deferred tax liabilities (as an offset to the associated deferred tax asset)
Income Tax Contingency [Line Items]
Unrecognized tax benefits	$ 6,485,000		$ 6,166,000
Scenario, Forecast
Income Tax Contingency [Line Items]
Federal income tax rate		27.00%
Effective tax rate		27.75%
Effective tax rate, prior estimate		34.50%