Commitments and Contingencies Environmental Matter (Details) $ in Millions	3 Months Ended
	Oct. 31, 2017 USD ($)
Environmental Matter Disclosure [Line Items]
Identified Remediation Plan, Cost Estimated by the EPA	$ 1,380.0
RoD Design Phase, Settlement Amount by Third Party	165.0
CPG Preferred Approach [Member] | Minimum [Member]
Environmental Matter Disclosure [Line Items]
Estimated Remediation Costs CPG Recommended Approach	$ 483.0