Goodwill and Intangible Assets Goodwill (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill [Line Items]
Goodwill, Gross	$ 340.9	$ 340.9
Goodwill, Impaired, Accumulated Impairment Loss [Abstract]
Goodwill, Impaired, Accumulated Impairment Loss	50.3	50.3
Goodwill [Roll Forward]
Goodwill	290.6	341.7
Impairment	0	(50.3)	0
Dispostion of home security business		(0.8)
Goodwill	290.6	290.6	341.7
Goodwill and Intangible Assets Disclosure [Abstract]
Gain on sale of assets	(1.6)	(8.4)	0
Wireless [Member]
Goodwill [Roll Forward]
Goodwill	0	50.3
Impairment	0	(50.3)
Dispostion of home security business		0
Goodwill	0	0
Wireline [Member]
Goodwill [Roll Forward]
Goodwill	11.8	12.6
Impairment	0	0
Dispostion of home security business		(0.8)
Goodwill	11.8	11.8
Data Center Colocation [Member]
Goodwill [Roll Forward]
Goodwill	276.3	276.3
Impairment	0	0
Dispostion of home security business		0
Goodwill	276.3	276.3
IT Services and Hardware [Member]
Goodwill [Roll Forward]
Goodwill	2.5	2.5
Impairment	0	0
Dispostion of home security business		0
Goodwill	2.5	2.5
Licensing Agreements [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 88.2	$ 88.2