Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Jun. 30, 2015 USD ($) customer facility	Jun. 30, 2014 USD ($) customer segment	Jun. 30, 2013 USD ($) customer segment	Nov. 30, 2012
Summary of significant accounting policies
Discounts, rebates, returns and allowances	$ 27.4	$ 28.3	$ 26.4
Inventory accounted under LIFO method	154.9	161.2
Research and development expenditures	18.7	18.5	19.4
Capitalized software amortization expense	$ 6.1	6.4	$ 6.8
Number of former operating facility site that the liability for future costs is discounted to present value | facility	1
Liability for future costs discount amortization period	20 years
Environmental expenditures, discount rate	4.00%
Environmental expenditures, liability	$ 10.8	$ 10.4
Number of customers accounted for 10% or more of the sales	0	0	0
Revenue | Customer
Summary of significant accounting policies
Concentration risk, number of customers | customer	0	0	0
Accounts receivable | Customer
Summary of significant accounting policies
Concentration risk, number of customers | customer	1	0
Concentration risk	17.00%
Minimum
Summary of significant accounting policies
Ownership interest (as a percent)	20.00%
Minimum | Computer software
Summary of significant accounting policies
Estimated useful life	3 years
Minimum | Intangible Assets
Summary of significant accounting policies
Estimated useful life	2 years 6 months
Maximum
Summary of significant accounting policies
Ownership interest (as a percent)	50.00%
Maximum | Computer software
Summary of significant accounting policies
Estimated useful life	7 years
Maximum | Intangible Assets
Summary of significant accounting policies
Estimated useful life	30 years
Carpenter Powder Products AB
Summary of significant accounting policies
Ownership interest (as a percent)				40.00%
Ownership interest of noncontrolling partner (as a percent)				40.00%
Sandvik Powdermet AB
Summary of significant accounting policies
Ownership interest (as a percent)				40.00%