CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Common Stock	Additional paid-in Capital	Accumulated Other Comprehensive (Loss)/Income	Accumulated Deficit	Notes receivable from shareholder	Total
Balance at Jun. 30, 2014	$ 0.2	$ 755.4	$ 14.4	$ (331.6)	$ (22.0)	$ 416.4
Balance, shares at Jun. 30, 2014	223,000,000
Proceeds from issuance of common stock		387.2				387.2
Proceeds from issuance of common stock, shares	20,008,679
Reclassification of common unit liability to additional paid in capital		490.2				490.2
Stock-based compensation		95.0				95.0
Non-cash settlement of note receivable from Communications Infrastructure Investments		(22.0)			$ 22.0
Foreign currency translation adjustments			(22.3)			(22.3)
Net income/(loss)				(155.3)		(155.3)
Balance at Jun. 30, 2015	$ 0.2	1,705.8	(7.9)	(486.9)		1,211.2
Balance, shares at Jun. 30, 2015	243,008,679
Stock-based compensation		152.9				152.9
Stock-based compensation, shares	3,114,939
Cumulative effect adjustment resulting from adoption of ASU 2016-09 (Note 1)						1.7
Foreign currency translation adjustments			12.4			12.4
Repurchase and retirement of common shares		(81.1)				(81.1)
Repurchase and retirement of common shares (in shares)	(3,474,120)
Net income/(loss)				(76.2)		(76.2)
Balance at Jun. 30, 2016	$ 0.2	1,777.6	4.5	(563.1)		$ 1,219.2
Balance, shares at Jun. 30, 2016	242,649,498					242,649,498
Stock-based compensation		104.7				$ 104.7
Stock-based compensation, shares	3,822,053
Cumulative effect adjustment resulting from adoption of ASU 2016-09 (Note 1)		1.7		(1.7)
Foreign currency translation adjustments			2.1			2.1
Defined benefit pension plan adjustments			(1.2)			(1.2)
Net income/(loss)				85.7		85.7
Balance at Jun. 30, 2017	$ 0.2	$ 1,884.0	$ 5.4	$ (479.1)		$ 1,410.5
Balance, shares at Jun. 30, 2017	246,471,551					246,471,551