Pension and Postretirement Benefit Plans (Schedule of fair value measurements for pension plan assets) (Details) - Pension - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Domestic
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	$ 139,000	$ 139,200	$ 122,600
Domestic | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	97,000	98,200
Domestic | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	40,400	40,700
Domestic | Pooled separate accounts
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	1,600	300
Domestic | Quoted Prices (Level 1)
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	74,000	76,800
Domestic | Quoted Prices (Level 1) | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	74,000	76,800
Domestic | Quoted Prices (Level 1) | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0	0
Domestic | Quoted Prices (Level 1) | Pooled separate accounts
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0	0
Domestic | Significant Other Observable Inputs (Level 2)
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	65,000	62,400
Domestic | Significant Other Observable Inputs (Level 2) | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	23,000	21,400
Domestic | Significant Other Observable Inputs (Level 2) | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	40,400	40,700
Domestic | Significant Other Observable Inputs (Level 2) | Pooled separate accounts
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	1,600	300
Domestic | Significant Unobservable Inputs (Level 3)
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0	0
Domestic | Significant Unobservable Inputs (Level 3) | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0	0
Domestic | Significant Unobservable Inputs (Level 3) | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0	0
Domestic | Significant Unobservable Inputs (Level 3) | Pooled separate accounts
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0	0
International
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	841,500	$ 0
International | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	155,100
International | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	242,000
International | Cash and cash equivalents
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	17,600
International | Other
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	415,800
International | Guaranteed investment contract
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	11,000
International | Quoted Prices (Level 1)
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	5,200
International | Quoted Prices (Level 1) | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Quoted Prices (Level 1) | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Quoted Prices (Level 1) | Cash and cash equivalents
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	5,200
International | Quoted Prices (Level 1) | Other
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Quoted Prices (Level 1) | Guaranteed investment contract
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Significant Other Observable Inputs (Level 2)
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	836,300
International | Significant Other Observable Inputs (Level 2) | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	155,100
International | Significant Other Observable Inputs (Level 2) | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	242,000
International | Significant Other Observable Inputs (Level 2) | Cash and cash equivalents
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	12,400
International | Significant Other Observable Inputs (Level 2) | Other
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	415,800
International | Significant Other Observable Inputs (Level 2) | Guaranteed investment contract
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	11,000
International | Significant Unobservable Inputs (Level 3)
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Significant Unobservable Inputs (Level 3) | Equity
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Significant Unobservable Inputs (Level 3) | Fixed Income
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Significant Unobservable Inputs (Level 3) | Other
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	0
International | Significant Unobservable Inputs (Level 3) | Guaranteed investment contract
Fair Value Measurements for Pension Assets [Abstract]
Fair value of plan assets	$ 0