Segment Information, Geographic and Product Data (Details 2) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Segment Data
Net sales	$ 558.0	$ 570.6	$ 548.4	$ 549.8	$ 604.6	$ 566.3	$ 503.5	$ 498.6	$ 2,226.7	$ 2,173.0	$ 2,271.7
Operating income	39.5	$ 4.8	$ 45.0	$ 22.1	59.2	$ 49.5	$ 47.5	$ 55.8	111.5	212.0	232.7
Depreciation and Amortization									122.3	111.9	104.1
Capital Expenditures									170.5	349.2	310.2
Assets	2,905.9				3,057.5				2,905.9	3,057.5
Operating
Segment Data
Pension EID									(9.4)	(21.8)	(31.9)
Corporate costs (including restructuring charges)
Segment Data
Operating income									(72.0)	(43.8)	(47.7)
Depreciation and Amortization									4.6	5.5	5.9
Capital Expenditures									4.3	5.4	4.1
Assets	125.0				144.9				125.0	144.9
Intersegment
Segment Data
Net sales									(67.6)	(67.2)	(71.9)
Operating income									(1.4)	(0.6)	(1.4)
Depreciation and Amortization									(0.6)	(0.8)	(0.6)
Capital Expenditures									(0.9)	(0.8)	(1.5)
Assets	(41.3)				(33.9)				(41.3)	(33.9)
Specialty Alloys Operations | Operating
Segment Data
Net sales									1,796.6	1,741.6	1,823.5
Operating income									155.2	232.7	268.5
Depreciation and Amortization									95.0	83.4	76.7
Capital Expenditures									129.0	319.9	283.5
Assets	2,323.0				2,454.8				2,323.0	2,454.8
Performance Engineered Products | Operating
Segment Data
Net sales									497.7	498.6	520.1
Operating income									39.1	45.5	45.2
Depreciation and Amortization									23.3	23.8	22.1
Capital Expenditures									38.1	24.7	$ 24.1
Assets	$ 499.2				$ 491.7				$ 499.2	$ 491.7