Balance Sheet Accounts - Summary of Impact of Land Sale (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended		9 Months Ended
	May. 31, 2015	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	May. 31, 2015	May. 31, 2014	Aug. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income tax provision related to land sale	$ 0.0		$ (0.6)		$ (0.1)	$ (0.6)
Net income from land sale	0.0	$ 0.2	$ (0.8)	$ 0.0	0.2	$ (0.8)	$ (0.6)
Hillsborough [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales from land sale	42.0				42.0
Cost of sales from land sale	11.4				11.4
Income from continuing operations before income taxes from land sale	30.6				30.6
Income tax provision related to land sale	12.7				12.7
Net income from land sale	$ 17.9				$ 17.9