Summary of Significant Accounting Policies (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Property and Equipment
Depreciation	$ 7,202	$ 6,801	$ 6,759
Furniture and equipment | Estimated lives, low end of the range
Property and Equipment
Estimated useful lives	2 years
Furniture and equipment | Estimated lives, high end of the range
Property and Equipment
Estimated useful lives	15 years
Buildings and improvements | Estimated lives, low end of the range
Property and Equipment
Estimated useful lives	5 years
Buildings and improvements | Estimated lives, high end of the range
Property and Equipment
Estimated useful lives	32 years