Consolidated Statement of Changes in Shareholder's Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss)/Income [Member]	Noncontrolling Interest [Member]
Beginning Balance at Jun. 30, 2014	$ (371.8)	$ 0.7	$ 1,031.4	$ (1,379.1)	$ (24.2)	$ (0.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity contribution	946.6	0.5	946.1
Equity compensation	9.0		9.0
Payments Related to Tax Withholding for Share-based Compensation	(10.3)		(10.3)
Noncontrolling Interest Ownership Changes	(1.5)		(2.5)			1.0
Net Income (Loss) Attributable to Parent	212.2			212.2
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest						(0.4)
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	211.8
Other comprehensive income /(loss), net of tax	(149.8)				(149.8)
Ending Balance at Jun. 30, 2015	634.0	1.2	1,973.7	(1,166.9)	(174.0)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity compensation	10.8		10.8
Payments Related to Tax Withholding for Share-based Compensation	(8.7)		(8.7)
Noncontrolling Interest Ownership Changes	(0.3)		(0.3)			0.0
Net Income (Loss) Attributable to Parent	111.5			111.5
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest						0.0
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	111.5
Other comprehensive income /(loss), net of tax	(131.7)				(131.7)
Ending Balance at Jun. 30, 2016	635.9	1.2	1,976.5	(1,036.1)	(305.7)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	20.3		1.0	19.3
Stock Issued During Period, Value, Stock Options Exercised	0.1	0.1
Equity compensation	20.9		20.9
Payments Related to Tax Withholding for Share-based Compensation	(5.4)		(5.4)
Net Income (Loss) Attributable to Parent	109.8			109.8
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	109.8
Other comprehensive income /(loss), net of tax	(8.4)				(8.4)
Ending Balance at Jun. 30, 2017	723.5	$ 1.3	1,992.0	(955.7)	$ (314.1)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ (29.4)		$ 0.0	$ (29.4)