DMC Pension Plan (Fair Value of Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 852.0	$ 819.5	$ 768.6
Fair value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	852.0	819.5
Fair value [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.4	10.6
Fair value [Member] | United States government obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.0	58.7
Fair value [Member] | Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	361.7	34.1
Fair value [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	463.8	524.7
Fair value [Member] | Alternative investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.1	169.3
Fair value [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.1
Fair value [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		22.0
Quoted prices in active markets for identical assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	848.8	101.2
Quoted prices in active markets for identical assets (Level 1) [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.3	10.6
Quoted prices in active markets for identical assets (Level 1) [Member] | United States government obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.0
Quoted prices in active markets for identical assets (Level 1) [Member] | Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	361.7
Quoted prices in active markets for identical assets (Level 1) [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	463.8	90.6
Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.1	549.0
Significant other observable inputs (Level 2) [Member] | Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.1
Significant other observable inputs (Level 2) [Member] | United States government obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	58.7
Significant other observable inputs (Level 2) [Member] | Corporate bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	34.1
Significant other observable inputs (Level 2) [Member] | Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	434.1
Significant other observable inputs (Level 2) [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.1
Significant other observable inputs (Level 2) [Member] | Asset-backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		22.0
Significant unobservable inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.1	169.3
Significant unobservable inputs (Level 3) [Member] | Alternative investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 3.1	$ 169.3