Fair Value Measurements - Hierarchy Levels (Details) - Recurring basis - USD ($)	Apr. 30, 2016	Jul. 31, 2015
Assets:
Total assets	$ 880,000	$ 1,680,000
Liabilities:
Total liabilities	1,855,000	2,777,000
Accrued expenses
Liabilities:
Assumed contingent obligation	12,000	12,000
Contingent guaranteed obligation	414,000	566,000
Total accrued expenses	426,000	578,000
Other long-term liabilities
Liabilities:
Contingent consideration	148,000	751,000
Assumed contingent obligation	1,126,000	1,126,000
Contingent guaranteed obligation	155,000	322,000
Total other long-term liabilities	1,429,000	2,199,000
Money markets | Cash and cash equivalents
Assets:
Money markets	880,000	1,680,000
Level 1
Assets:
Total assets	880,000	1,680,000
Level 1 | Money markets | Cash and cash equivalents
Assets:
Money markets	880,000	1,680,000
Level 3
Liabilities:
Total liabilities	1,855,000	2,777,000
Level 3 | Accrued expenses
Liabilities:
Assumed contingent obligation	12,000	12,000
Contingent guaranteed obligation	414,000	566,000
Total accrued expenses	426,000	578,000
Level 3 | Other long-term liabilities
Liabilities:
Contingent consideration	148,000	751,000
Assumed contingent obligation	1,126,000	1,126,000
Contingent guaranteed obligation	155,000	322,000
Total other long-term liabilities	$ 1,429,000	$ 2,199,000