Pension and Defined Contribution Plans - Fair Value Measurements and Benefit Payments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Aug. 31, 2013		Aug. 31, 2012		Aug. 31, 2011
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
Contributions to Multi-employer Pension Plans	$ 0.3		$ 0.2		$ 0.2
Percentage Funded (less than 65%)	65.00%
Defined Contribution Pension
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Defined contribution plan, cost recognized	4.7		4.1		4.1
Common stock included in defined contribution plan, market value	9.1
Common stock included in defined contribution plan as precentage of total fair value of assets in plan	3.80%
Domestic Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	105.7		95.6		83.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	105.7		95.6		83.9
Employer expected contribution to defined benefit plans in next fiscal year	8.7
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2014	7.0
2015	7.1
2016	7.2
2017	7.6
2018	8.4
2019-2023	47.5
Domestic Plans | Mutual Funds: Large blend fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	39.1		35.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	39.1		35.6
Domestic Plans | Mutual Funds: Foreign large blend fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	10.6		9.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	10.6		9.2
Domestic Plans | Mutual Funds: Small Blend Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	12.4		10.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	12.4		10.0
Domestic Plans | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	5.1		4.7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	5.1		4.7
Domestic Plans | Short-Term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	5.1		5.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	5.1		5.3
Domestic Plans | Fixed-Income Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	33.4		30.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	33.4		30.8
Domestic Plans | Level 1 | Mutual Funds: Large blend fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	39.1		35.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	39.1		35.6
Domestic Plans | Level 1 | Mutual Funds: Foreign large blend fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	10.6		9.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	10.6		9.2
Domestic Plans | Level 1 | Mutual Funds: Small Blend Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	12.4		10.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	12.4		10.0
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	5.1		5.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	5.1		5.3
Domestic Plans | Level 1 | Fixed-Income 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 | Mutual Funds: Large blend 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 | Mutual Funds: Foreign large blend 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 | Mutual Funds: Small Blend 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 | 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 | Fixed-Income Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	33.4		30.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	33.4		30.8
Domestic Plans | Level 3 | Mutual Funds: Large blend 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 3 | Mutual Funds: Foreign large blend 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 3 | Mutual Funds: Small Blend 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 3 | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	5.1		4.7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	4.7		4.2
Net unrealized gain relating to instruments still held at the reporting date	0.3		0.4
Shares purchased, including from dividend reinvestment	0.1		0.1
Fair value of plan assets at end of year	5.1		4.7
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 | Fixed-Income 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
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	30.1		28.1		26.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	30.1		28.1		26.5
Employer expected contribution to defined benefit plans in next fiscal year	1.1
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2014	1.0
2015	1.0
2016	1.0
2017	1.1
2018	1.1
2019-2023	6.0
International Plans | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	19.0		18.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	19.0		18.9
International Plans | Real Estate Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	1.4		1.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	1.4		1.4
International Plans | Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	3.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	3.0
International Plans | Short-Term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category			7.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year			7.8
International Plans | Fixed-Income Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	6.7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	6.7
International Plans | Level 1 | 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 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 | Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0
International Plans | Level 1 | Short-Term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category			0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year			0
International Plans | Level 1 | Fixed-Income Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0
International Plans | Level 2 | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	19.0		18.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	19.0		18.9
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 | Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	3.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	3.0
International Plans | Level 2 | Short-Term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category			7.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year			7.8
International Plans | Level 2 | Fixed-Income Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	6.7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	6.7
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	1.4		1.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1.4		0.6
Shares purchased, including from dividend reinvestment	0	[1]	0.8	[1]
Fair value of plan assets at end of year	1.4		1.4
International Plans | Level 3 | Multi-strategy investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	0
International Plans | Level 3 | Short-Term Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category			0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year			0
International Plans | Level 3 | Fixed-Income Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets by major category	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at end of year	$ 0

[1] Activity in 2013 was less than $0.1.