Consolidated Statement of Changes in Shareholder's Equity - 3 months ended Sep. 30, 2017 - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Jun. 30, 2017	$ 723.5	$ 1.3	$ 1,992.0	$ (955.7)	$ (314.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity Contribution	277.8	0.0	277.8
Equity compensation	7.0		7.0
Payments Related to Tax Withholding for Share-based Compensation	(8.4)		(8.4)
Net Income (Loss) Attributable to Parent	3.8			3.8
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	3.8
Other comprehensive income/(loss), net tax	35.1				35.1
Ending Balance at Sep. 30, 2017	$ 1,038.8	$ 1.3	$ 2,268.4	$ (951.9)	$ (279.0)