Acquisition and Strategic Partnership (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended			1 Months Ended	12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010	Feb. 29, 2012 Latrobe Acquisition	Jun. 30, 2012 Latrobe Acquisition	Jun. 30, 2011 Latrobe Acquisition	Jun. 30, 2010 Latrobe Acquisition	Dec. 15, 2011 Arwin
Acquisition and strategic partnership disclosures
Shares issued through business acquisition												8.1
Cash paid, net of cash acquired									$ 12.9	$ 45.4		$ 11.5
Cash acquired												2.5
Summary of preliminary purchase price allocation
Accounts receivable												67.3
Inventory												241.2
Property, plant and equipment												172.4				0.7
Intangible assets												87.1
Other												10.6
Accounts Payable and accrued liabilities												(63.9)
Long-term debt												(153.7)
Pension and other postretirement liabilities												(100.8)
Deferred income taxes												(47.7)
Total identifiable net assets												212.5
Goodwill												214.5				0.7
Total purchase price												427.0				1.4
Additional disclosure
Acquisition-related costs									11.7	3.1			11.7	2.4
Transaction costs													5.2
Net sales	643.7	539.9	431.1	414.1	483.6	464.2	375.6	351.7	2,028.7	1,675.1	1,198.6		163.2
Operating income since acquisition	66.5	55.7	43.9	44.0	35.0	35.2	12.1	14.1	210.1	96.4	11.7		10.5
Fair value cost inventory adjustments													11.6
Proforma results
Revenue													2,339.6	2,125.3	1,504.8
Earnings													$ 160.1	$ 93.5	$ (0.4)
Earnings per Common Share, Basic (in dollars per share)													$ 3.04	$ 1.78	$ (0.02)
Earnings per Common Share, Diluted (in dollars per share)													$ 3.01	$ 1.77	$ (0.02)