Employee Benefit Plans Employee Benefit Plans (Investments of the Plan Measured at Fair Value) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 2,006.3	$ 2,009.8	$ 2,024.1
Comingled Trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,029.2	1,082.7
Comingled Trusts [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Comingled Trusts [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,029.2	1,082.7
Comingled Trusts [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	371.5	270.7
US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	371.5	270.7
US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	76.6	89.0
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	76.6	89.0
Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mutual Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Corporate And Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	433.4	347.5
Corporate And Municipal Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Corporate And Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	433.4	347.5
Corporate And Municipal Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	35.3	34.5
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	35.3	34.5
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0.0	0.0
Total Pension Assets Excluding Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,946.0	1,824.4
Total Pension Assets Excluding Cash [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	76.6	89.0
Total Pension Assets Excluding Cash [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,869.4	1,735.4
Total Pension Assets Excluding Cash [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 0.0	$ 0.0