Stock-Based Compensation Income Tax Benefit From Stock-based Awards (Details) - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013	Aug. 01, 2005
Income Tax Benefits From Stock Based Awards [Abstract]
Actual income tax benefit recorded for the tax deductions relating to the settlement of stock-based awards	$ 1,108,000	$ 2,339,000	$ 420,000
Less: Tax benefit initially recognized on settled stock-based awards vesting subsequent to the adoption of accounting standards that require us to expense stock-based awards	960,000	1,540,000	155,000
Excess income tax benefit recorded as an increase to additional paid-in capital	148,000	799,000	265,000
Less: Tax benefit initially disclosed but not previously recognized on settled equity-classified stock-based awards vesting prior to the adoption of accounting standards that require us to expense stock-based awards	0	61,000	0
Excess income tax benefit from settled equity-classified stock-based awards reported as a cash flow from financing activities in our Consolidated Statements of Cash Flows	148,000	738,000	265,000
Hypothetical tax benefits related to stock-based awards	17,220,000	17,574,000		$ 8,593,000
Net reduction to APIC and hypothetical tax benefits, primarily due to the reversal of unrealized DTA associated with certain vested equity-classified stock-based awards that expired during the period	$ 354,000	$ 2,407,000	$ 2,805,000