Defined Contribution Plan, Common Stock Percentage of Total Fair Value of Plan Assets

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Number of Multiemployer Plans

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Value of all classes of common stock held by shareholders. May be all or portion of the number of common shares authorized. These shares exclude common shares repurchased by the entity and held as treasury shares.

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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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- Definition

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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- Definition

Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year.

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

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- Definition

Amount of cost for defined contribution plan.

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Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan.

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Pension and Defined Contribution Plans - Fair Value Measurements and Benefit Payments (Details) $ in Millions	12 Months Ended
	Aug. 31, 2020 USD ($) multiemployer_plan	Aug. 31, 2019 USD ($)	Aug. 31, 2018 USD ($)
Pension Plan
Multiemployer Plan, Pension, Significant [Abstract]
Number of multi-employer plans \| multiemployer_plan	2
Contributions to multi-employer plans	$ 0.6	$ 0.5	$ 0.5
Defined Contribution Plan
Defined Benefit Plan, Additional Information [Abstract]
Defined contribution plan, cost recognized	8.2	8.1	8.0
Common stock included in defined contribution plan, market value	$ 5.9
Common stock included in defined contribution plan as percentage of total fair value of assets in plan	1.50%
Domestic Plans \| Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	$ 167.1	151.5	149.4
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	12.8
2022	11.7
2023	23.3
2024	17.9
2025	13.0
2026-2030	67.6
Domestic Plans \| Pension Plan \| Level 1 \| Mutual Funds: Domestic large cap equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	55.6	45.6
Domestic Plans \| Pension Plan \| Level 1 \| Mutual Funds: Foreign equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	26.0	20.5
Domestic Plans \| Pension Plan \| Level 1 \| Collective trust: Domestic small cap equities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 1 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	5.2	6.0
Domestic Plans \| Pension Plan \| Level 2 \| Mutual Funds: Domestic large cap equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 2 \| Mutual Funds: Foreign equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 2 \| Collective trust: Domestic small cap equities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	15.7	14.6
Domestic Plans \| Pension Plan \| Level 2 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 3 \| Mutual Funds: Domestic large cap equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 3 \| Mutual Funds: Foreign equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 3 \| Collective trust: Domestic small cap equities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 3 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Domestic Plans \| Pension Plan \| Level 1,2 and 3
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	102.5	86.7
Domestic Plans \| Pension Plan \| Level 1,2 and 3 \| Mutual Funds: Domestic large cap equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	55.6	45.6
Domestic Plans \| Pension Plan \| Level 1,2 and 3 \| Mutual Funds: Foreign equity fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	26.0	20.5
Domestic Plans \| Pension Plan \| Level 1,2 and 3 \| Collective trust: Domestic small cap equities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	15.7	14.6
Domestic Plans \| Pension Plan \| Level 1,2 and 3 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	5.2	6.0
Domestic Plans \| Pension Plan \| NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	64.6	64.8
Domestic Plans \| Pension Plan \| NAV \| Fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	57.0	57.4
Domestic Plans \| Pension Plan \| NAV \| Real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	7.6	7.4
International Plans \| Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	35.1	30.7	$ 30.9
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	1.1
2022	1.2
2023	1.2
2024	1.3
2025	1.3
2026-2030	7.5
International Plans \| Pension Plan \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	27.0	22.4
International Plans \| Pension Plan \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.3	0.3
International Plans \| Pension Plan \| Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	3.3	3.0
International Plans \| Pension Plan \| Fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	4.5	5.0
International Plans \| Pension Plan \| Level 1 \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 1 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.3	0.3
International Plans \| Pension Plan \| Level 1 \| Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 1 \| Fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 2 \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	27.0	22.4
International Plans \| Pension Plan \| Level 2 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 2 \| Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	3.3	3.0
International Plans \| Pension Plan \| Level 2 \| Fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	4.5	5.0
International Plans \| Pension Plan \| Level 3 \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 3 \| Short-term fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 3 \| Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
International Plans \| Pension Plan \| Level 3 \| Fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	$ 0.0
Qualified Plan \| Domestic Plans \| Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer expected contribution to defined benefit plans in next fiscal year	1.0
Qualified Plan \| International Plans \| Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer expected contribution to defined benefit plans in next fiscal year	$ 1.2