Credit Facility (Details) - USD ($)	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Dec. 09, 2015
Uncommitted Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of Credit Facility, maximum borrowing capacity	$ 15,000,000
Line of Credit Facility, expiration date	Oct. 31, 2016
Outstanding standby letters of credit at period end	$ 1,794,000
Outstanding commercial letters of credit at period end	0
Interest expense related to Credit Facility	$ 0
Committed Secured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, maximum borrowing capacity		$ 100,000,000
Line of Credit Facility, expiration date		Oct. 31, 2014
Interest expense related to Credit Facility		$ 198,000
Commitment for the TCS Acquisition Related Credit Facility | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, maximum borrowing capacity			$ 400,000,000