The maximum amount of contributions per share-based compensation plan during the offering period.

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Stock Issued During Period Employee Stock Purchase Plans Weighted Average Price Per Share

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Aggregate number of common shares reserved for future issuance.

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

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Weighted-average period over which cost not yet recognized is expected to be recognized for 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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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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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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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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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Gross number of share options (or share units) granted during the period.

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No definition available.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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No definition available.

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Percentage of vesting of award under share-based payment arrangement.

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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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Purchase price of common stock expressed as a percentage of its fair value.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Employee and Non-employee Director Stock Option and Retirement Plans - Narrative (Details) - USD ($)			3 Months Ended		9 Months Ended
	Jan. 15, 2020	Nov. 01, 2019	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price (in USD per share)		$ 255.87
Purchase price (in percentage)					85.00%
Maximum employee subscription rate (in percentage)			10.00%		10.00%
Maximum contribution limit					$ 25,000
Number of share purchased by employees (in shares)			11,084	13,350	33,735	39,069
Stock issued during period employee stock purchase plans weighted average price per share (in USD per share)			$ 238.81	$ 201.54	$ 226.79	$ 199.43
Capital shares reserved for future issuance (in shares)			186,675		186,675
Stock-based compensation expense			$ 10,300,000	$ 8,000,000.0	$ 28,400,000	$ 24,100,000
Unrecognized compensation expense related to non-vested equity			$ 89,100,000		$ 89,100,000
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)					422,346
Weighted average exercise price (in USD per share)					$ 256.05
Number of shares available for grant (in shares)			5,600,000		5,600,000
Director Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)			247,876		247,876
Director Plan \| Non-employee \| Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	16,080
Award vesting period	3 years
Expiration period	7 years
Weighted average grant date fair value (in USD per share)	$ 54.74
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 600,000	$ 600,000	$ 1,600,000	$ 1,600,000
Weighted average period for recognition			3 years 1 month 6 days
Stock options \| LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)		412,098
Award vesting (in percentage)		20.00%
Award vesting period		5 years
Stock options \| LTIP \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period		10 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option award grants (in shares)					30,766
RSUs \| LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)					29,817
Award vesting period					5 years
Weighted average grant date fair value (in USD per share)					$ 245.48
RSUs \| LTIP \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting (in percentage)					20.00%
PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option award grants (in shares)					36,909
PRSUs \| LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)					36,501
Award vesting period					3 years