Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2015	Jul. 31, 2015	Oct. 31, 2014
Holland Creek Metropolitan District [Member]
Credit-enhanced bonds issued amount	$ 8,000
Amount outstanding in letters of credit	8,100
Red Sky Ranch Metropolitan District [Member]
Other long-term liabilities	$ 1,800	$ 1,800	$ 1,800
Estimated cessation date of capital improvement fee payment obligation	Jul. 31, 2029
Various Other [Member]
Amount outstanding in letters of credit	$ 64,600
Employee Housing Bonds [Member]
Amount outstanding in letters of credit	53,400
Workers' Compensation and General Liability Related to Construction and Development Activities [Member]
Amount outstanding in letters of credit	$ 11,200