Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised	$ 14.8
Options granted, grant date fair value (in usd per share)	$ 10.94	$ 12.27
Aggregate intrinsic value of options outstanding	$ 71.8
Aggregate intrinsic value of options exercisable	69.5
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	10.2
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	5.0
Fair value of awards granted	$ 5.2
2010 Master Stock Incentive Plan \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercisable term (in years)	10 years
Stock option, award vesting period (in years)	3 years
2010 Master Stock Incentive Plan \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance award measurement period (in years)	3 years
Expiration period (in years)	3 years
Minimum \| 2010 Master Stock Incentive Plan \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payout percentage based on target award (percentage)	0.00%
Maximum \| 2010 Master Stock Incentive Plan \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payout percentage based on target award (percentage)	200.00%

Share-Based Compensation Arrange By Share-Based Payment Award, Award Target Payout, Percentage

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Share-based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Aggregate Intrinsic Value, Granted

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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