Supplemental Disaggregated Information (Details) $ in Millions		3 Months Ended								12 Months Ended
		Aug. 31, 2016 USD ($)	May 31, 2016 USD ($)	Feb. 29, 2016 USD ($)	Nov. 30, 2015 USD ($)	Aug. 31, 2015 USD ($)	May 31, 2015 USD ($)	Feb. 28, 2015 USD ($)	Nov. 30, 2014 USD ($)	Aug. 31, 2016 USD ($) Segment		Aug. 31, 2015 USD ($)		Aug. 31, 2014 USD ($)
Geographic Distribution
Number of reportable segments | Segment										1
Net sales		$ 925.5	$ 851.5	$ 777.8	$ 736.6	$ 759.5	$ 683.7	$ 616.1	$ 647.4	$ 3,291.3	[1]	$ 2,706.7	[1]	$ 2,393.5	[1]
Operating profit										475.2		376.3		299.1
Income before Provision for Income Taxes										444.6		343.6		265.7
Long-lived assets		295.9				205.2				295.9		205.2		179.5
Domestic
Geographic Distribution
Net sales	[1],[2]									2,928.3		2,450.1		2,155.0
Operating profit										457.6		364.0		287.8
Income before Provision for Income Taxes										430.8		329.4		257.1
Long-lived assets		254.5				179.6				254.5		179.6		148.3
International
Geographic Distribution
Net sales	[1]									363.0		256.6		238.5
Operating profit										17.6		12.3		11.3
Income before Provision for Income Taxes										13.8		14.2		8.6
Long-lived assets		$ 41.4				$ 25.6				$ 41.4		$ 25.6		$ 31.2
Sales of lighting solutions, excluding services | Product Concentration Risk
Geographic Distribution
Sales as percentage of total sales										99.00%		99.00%		99.00%

[1] Net sales are attributed to each country based on the selling location.

[2] Domestic amounts include net sales (including export sales), operating profit, income before provision for income taxes, and long-lived assets for U.S. based operations.