Pension and Profit Sharing Plans - Fair Value Measurements and Benefit Payments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2009
Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	$ 83.9	$ 75.7	$ 75.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	83.9	75.7	75.3
Employer expected contribution to defined benefit plans in next fiscal year	9.4
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2012	6.5
2013	6.6
2014	6.8
2015	7.0
2016	7.2
2017-2021	43.3
Domestic Plans | Level 1 | Mutual Funds: US equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	30.1	26.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	30.1	26.2
Domestic Plans | Level 1 | Mutual Funds: International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	9.1	8.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	9.1	8.3
Domestic Plans | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	9.2	7.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	9.2	7.6
Domestic Plans | Level 1 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 1 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	2.5	2.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	2.5	2.0
Domestic Plans | Level 1 | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 2 | Mutual Funds: US equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 2 | Mutual Funds: International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 2 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 2 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 2 | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	28.8	28.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	28.8	28.1
Domestic Plans | Level 3 | Mutual Funds: US equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 3 | Mutual Funds: International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 3 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	4.2	3.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	3.5	3.1
Income	0.2	0.2
Net unrealized gain (loss) relating to instruments still held at the reporting date	0.4	(0.8)
Shares purchased from dividend reinvestment	0.1	1.0
Fair value of plan assets at end of year	4.2	3.5
Domestic Plans | Level 3 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Level 3 | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
Domestic Plans | Mutual Funds: US equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	30.1	26.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	30.1	26.2
Domestic Plans | Mutual Funds: International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	9.1	8.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	9.1	8.3
Domestic Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	9.2	7.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	9.2	7.6
Domestic Plans | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	4.2	3.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	4.2	3.5
Domestic Plans | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	2.5	2.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	2.5	2.0
Domestic Plans | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	28.8	28.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	28.8	28.1
International Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	26.5	21.8	21.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	26.5	21.8	21.3
Employer expected contribution to defined benefit plans in next fiscal year	1.1
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2012	0.5
2013	0.5
2014	0.6
2015	0.7
2016	0.9
2017-2021	4.9
International Plans | Level 1 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	20.3	18.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	20.3	18.3
International Plans | Level 1 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 1 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	1.6	1.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	1.6	1.3
International Plans | Level 1 | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 2 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 2 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 2 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 2 | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	4.0	1.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	4.0	1.8
International Plans | Level 3 | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 3 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0.6	0.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0.4	0.3
Net unrealized gain (loss) relating to instruments still held at the reporting date	0	0.1
Shares purchased from dividend reinvestment	0.2	0
Fair value of plan assets at end of year	0.6	0.4
International Plans | Level 3 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Level 3 | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0	0
International Plans | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	20.3	18.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	20.3	18.3
International Plans | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0.6	0.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0.6	0.4
International Plans | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	1.6	1.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	1.6	1.3
International Plans | Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	4.0	1.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	4.0	1.8
Defined Contribution Pension
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution plan, cost recognized	4.1	4.0	4.3
Common stock included in defined contribution plan, market value	$ 6.2
Common stock included in defined contribution plan as precentage of total fair value of assets in plan	3.10%