Fair Value Measurements - Hierarchy Levels (Details) - Recurring basis - USD ($)	Oct. 31, 2016	Jul. 31, 2016
Assets:
Total assets	$ 740,000	$ 740,000
Liabilities:
Total liabilities	1,487,000	1,579,000
Accrued expenses
Liabilities:
Assumed contingent obligation	12,000	12,000
Contingent guaranteed obligation	309,000	366,000
Total accrued expenses	321,000	378,000
Other long-term liabilities
Liabilities:
Assumed contingent obligation	1,126,000	1,126,000
Contingent guaranteed obligation	40,000	75,000
Total other long-term liabilities	1,166,000	1,201,000
Money markets | Cash and cash equivalents
Assets:
Money markets	740,000	740,000
Level 1
Assets:
Total assets	740,000	740,000
Level 1 | Money markets | Cash and cash equivalents
Assets:
Money markets	740,000	740,000
Level 3
Liabilities:
Total liabilities	1,487,000	1,579,000
Level 3 | Accrued expenses
Liabilities:
Assumed contingent obligation	12,000	12,000
Contingent guaranteed obligation	309,000	366,000
Total accrued expenses	321,000	378,000
Level 3 | Other long-term liabilities
Liabilities:
Assumed contingent obligation	1,126,000	1,126,000
Contingent guaranteed obligation	40,000	75,000
Total other long-term liabilities	$ 1,166,000	$ 1,201,000