Income Taxes Income/(Loss) from Continuing Operations Before Income Tax) (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Jun. 30, 2015	[1]	Mar. 31, 2015	[1],[2],[3]	Dec. 31, 2014	[1]	Sep. 30, 2014	[1]	Jun. 30, 2014	[4],[5]	Mar. 31, 2014	[4],[6]	Dec. 31, 2013	[4],[7],[8]	Sep. 30, 2013	[4]	Jun. 30, 2015		Jun. 30, 2014		Jun. 30, 2013
Income Tax Disclosure [Abstract]
United States																	$ (159.7)		$ (135.3)		$ (185.6)
Foreign																	(4.4)		(9.0)		15.8
Loss from operations before income taxes	$ 9.7		$ (72.1)		$ (0.6)		$ (101.1)		$ (62.1)		$ (33.2)		$ (29.2)		$ (19.8)		$ (164.1)	[1]	$ (144.3)	[4]	$ (169.8)

[1] The Company realized an increase in revenue and operating expenses beginning July 1, 2014 as a result of the acquisition of AtlantaNap and Neo.

[2] The Company realized an increase in revenue and operating expenses beginning February 23, 2015 as a result of the acquisition of Latisys.

[3] The Company realized an increase in revenue and operating expenses beginning January 1, 2015 as a result of the acquisition of IdeaTek.

[4] The Company realized an increase in revenue and operating expenses beginning August 1, 2013 as a result of the acquisition of Corelink.

[5] The Company realized an increase in revenue and operating expenses beginning May 16, 2014 as a result of the acquisition of Geo.

[6] The Company realized an increase in revenue and operating expenses beginning March 4, 2014 as a result of the acquisition of CoreXchange.

[7] The Company realized an increase in revenue and operating expenses beginning October 1, 2013 as a result of the acquisition of Access.

[8] The Company realized an increase in revenue and operating expenses beginning October 2, 2013 as a result of the acquisition of Fiberlink.