Stock-Based Compensation - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Stock-Based Compensation (Additional Textual) [Abstract]
Maximum period of achievement of performance goals to earn performance units	3 years
Minimum performance period of individual required to earn performance units	3 years
Stock Option [Member]
Stock-Based Compensation (Textual) [Abstract]
Compensation expense related to stock option	$ 0.1	$ 0.7	$ 1.5
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	1.2	1.9	3.3
Tax benefits resulting from stock-based compensation deductions in excess of amounts reported for financial reporting purposes	1.3		0.0
Cash received from the exercise of capital stock option	4.8	22.2	21.3
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	0.5	1.4	0.0
Total Intrinsic value of options exercised	2.4	6.6	3.1
Restricted Stock Units - Time Vesting Performance Vesting [Member]
Stock-Based Compensation (Textual) [Abstract]
Compensation expense related to stock option	21.9	$ 19.4	$ 19.3
Unrecognized compensation cost	$ 17.7
Unrecognized compensation costs, weighted average period	1 year 11 months

Maximum period of achievement of performance goals to earn performance units.

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Stock-based compensation.

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Stock based compensation.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

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Amount of cash inflow from realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.

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Amount of cash inflow from exercise of stock options granted under share-based compensation 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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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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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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