Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Defined Contribution Plans [Abstract]
Employer matching contribution percentage	100.00%
Employee contribution	4.00%
Total plan expense	$ 1.4	$ 1.2	$ 1.7

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration