Acquisitions and Dispositions (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009 tower Years	Dec. 31, 2009 Wireless Towers [Member]	Dec. 31, 2009 Virtual Blocks Inc and Cintech LLC [Member]	Jun. 11, 2010 Cyrus Networks [Member]
Business Acquisition, Cost of Acquired Entity, Purchase Price [Abstract]
Business Acquisition, Cost of Acquired Entity, Purchase Price					$ 2.5	$ 526.0
Business Acquisition, Purchase Price Allocation [Abstract]
Receivables						10.4
Other current assets						0.5
Property, plant and equipment						153.6
Goodwill						269.6
Intangible assets						138.0
Other noncurrent assets						0.1
Total assets acquired						572.2
Accounts payable						3.1
Unearned revenue and customer deposits						7.7
Accrued taxes						1.5
Accrued payroll and benefits						0.7
Other current liabilities						0.8
Noncurrent liabilities						32.1
Total liabilities assumed						45.9
Net assets acquired						526.3
Business Acquisition, Pro Forma Information [Abstract]
Revenue		1,408.6	1,392.7
Net income		23.3	65.1
Basic earnings per common share		$ 0.06	$ 0.26
Diluted earnings per common share		$ 0.06	$ 0.25
Disposition of Assets [Abstract]
Proceeds from sale of assets	11.5	0	105.9	99.9
Amortization period for deferred gain			20
Loss on sale of assets	8.4	0	(4.8)
Wireless Towers (number of towers)			196
Deferred Gain on Sale of Property	$ 41.7	$ 44.0