Employee Benefit Plans (Pension Plan Target Allocation) (Details) - Pension Plan	Jul. 31, 2019
Salaried Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	100.00%
Salaried Pension Plan | Global equity securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	33.00%
Salaried Pension Plan | Private equity and other funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	65.00%
Salaried Pension Plan | Real asset funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	1.00%
Salaried Pension Plan | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	1.00%
Hourly Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	100.00%
Hourly Pension Plan | Global equity securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	37.00%
Hourly Pension Plan | Private equity and other funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	60.00%
Hourly Pension Plan | Real asset funds
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	2.00%
Hourly Pension Plan | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Pension plan target allocation percentage	1.00%