Assets Held-for-Sale, Discontinued Operations, and Dispositions (Amounts Applicable to Discontinued Operations in Income) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss from discontinued operations, net of income taxes	$ 0.1	$ (14.7)	$ 0.0	$ 0.0	$ 0.0	$ 0.0	$ 0.0	$ 0.0	$ (14.6)	$ 0.0	$ 0.0
Loss per share from discontinued operations, basic (in usd per share)									$ (0.32)	$ 0.00	$ 0.00
Loss per share from discontinued operations, diluted (in usd per share)									$ (0.32)	$ 0.00	$ 0.00
Discontinued operations, held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues									$ 262.0
Costs and expenses									(250.6)
Interest expense									(12.2)
Loss on disposal									(12.3)
Loss before income taxes									(13.1)
Income taxes									(1.5)
Loss from discontinued operations, net of income taxes									$ (14.6)
Loss per share from discontinued operations, basic (in usd per share)									$ (0.32)
Loss per share from discontinued operations, diluted (in usd per share)									$ (0.32)