Stock-Based Compensation - Summary of Incentive Equity Awards - Additional Information (Details) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended	6 Months Ended
Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised during period, aggregate intrinsic value		$ 2.5	$ 38.7
Outstanding vested and currently exercisable stock options (in shares) \| shares	2.1	2.1	2.1
Exercisable stock options, aggregate intrinsic value	$ 120.5	$ 120.5	$ 120.5
Exercisable stock options, weighted average exercise price \| $ / shares	$ 39.12	$ 39.12	$ 39.12
Exercisable stock options, weighted average remaining contractual life		4 years 11 months 23 days
Stock options outstanding, weighted-average remaining contractual life	6 years 6 months
Closing stock price (in dollars per share) \| $ / shares	$ 96.25	$ 96.25	$ 96.25
Time-based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units expected to vest (in shares) \| shares	1.1	1.1	1.1
Restricted stock units, aggregate intrinsic value	$ 110.4	$ 110.4	$ 110.4
Performance-based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units expected to vest (in shares) \| shares	0.5	0.5	0.5
Restricted stock units, aggregate intrinsic value	$ 46.3	$ 46.3	$ 46.3

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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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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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Price of a single share of a number of saleable stocks of a company.

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Intrinsic value of equity-based compensation awards not vested. Excludes stock and unit options.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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