Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions |
6 Months Ended | ||
|---|---|---|---|
Jan. 31, 2017 |
Jul. 31, 2016 |
Jan. 31, 2016 |
|
| Amount outstanding in letters of credit | $ 66.1 | ||
| Surety Bonds Outstanding | 9.3 | ||
| Holland Creek Metropolitan District [Member] | |||
| Credit-enhanced bonds issued amount | 8.0 | ||
| Amount outstanding in letters of credit | 8.1 | ||
| Red Sky Ranch Metropolitan District [Member] | |||
| Other long-term liabilities | $ 2.0 | $ 2.0 | $ 1.8 |
| Estimated cessation date of capital improvement fee payment obligation | Jul. 31, 2031 | ||
| Employee Housing Bonds [Member] | |||
| Amount outstanding in letters of credit | $ 53.4 | ||
| Workers' Compensation and General Liability Related to Construction and Development Activities [Member] | |||
| Amount outstanding in letters of credit | $ 12.7 |