Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014
Proceeds from Sale of Intangible Assets		$ 194.4
Indefinite-Lived Intangible Assets (Excluding Goodwill)		88.2
Prepaid Expense, Current	14.1				10.8
Gain on Liabilities and Other Assets transferred in Sale of Business Affiliate and Productive Assets			16
Total liabilities	2,332.6				2,469.2
Revenue	292.9			282.2
Selling, General and Administrative Expense	52.2			49.3
Depreciation and amortization	61.2			46.9
Restructuring charges	3.4			0
Amortization of deferred gain	6.5			3.6
Total operating costs and expenses	255.8			231.8
Operating income (loss)	37.1			50.4
Other Nonoperating Income (Expense)	(0.4)			0.3
Gain on sale of wireless spectrum licenses	(112.6)			0
Income tax expense	0.6			6.5
Net income from discontinued operations	49.2			7.0
Other current assets	3.5				1.8
Other noncurrent assets	32.4				33.9
Total noncurrent assets from discontinued operations	16.0				44.6
Restructuring reserve	3.5				4.9
Other current liabilities from discontinued operations	26.5				142.0
Other noncurrent liabilities	39.3				26.2
Total noncurrent liabilities from discontinued operations	31.2				102.7
Restructuring payments	(4.5)
Capital expenditures	(57.9)			(34.3)
Discontinued Operations [Member]
Prepaid Expense, Current		6.4
Total liabilities	31.7
Other noncurrent liabilities from discontinued operations	6.6
Revenue	4.4			44.7
Cost of Goods and Services Sold	12.0			19.8
Selling, General and Administrative Expense	1.3			6.2
Depreciation and amortization	28.6			15.8
Restructuring charges	6.4			0
Amortization of deferred gain	(6.5)			(3.6)
Total operating costs and expenses	41.8			38.2
Operating income (loss)	(37.4)			6.5
Interest Income (Expense), Net	(0.8)			1.5
Other Nonoperating Income (Expense)	0			0.9
Gain on sale of wireless spectrum licenses	(112.6)			0
Income before income taxes	76.0			4.1
Income tax expense	27.1			3.0
Net income from discontinued operations	48.9			1.1
Prepaid rent - spectrum license	0				3.2
Other current assets	0.4				1.5
Total current assets from discontinued operations	0.4				4.7
Property, plant and equipment, net	16.0				44.1
Other noncurrent assets	0				0.5
Total noncurrent assets from discontinued operations	16.0				44.6
Total assets from discontinued operations	16.4				49.3
Current portion of long-term debt	0.5				1.6
Accounts payable	2.8				5.0
Restructuring reserve	18.4				15.4
Deferred Gain on Sale of Property	0				112.6
Other current liabilities from discontinued operations	4.8				7.4
Total current liabilities from discontinued operations	26.5				142.0
Long-term debt, less current portion	24.6				81.6
Other noncurrent liabilities	0				8.0
Total noncurrent liabilities from discontinued operations	31.2				102.7
Disposal Group, Including Discontinued Operation, Liabilities	57.7				244.7
Increase (Decrease) in Prepaid Rent	3.2			0
Restructuring payments	(3.4)			(0.3)
Capital expenditures	0			5.6
Continuing Operations [Member]
Total liabilities	65.4				65.6
Depreciation and amortization	32.6			31.1
Net income from discontinued operations				5.9
Current portion of long-term debt	1.1				1.1
Long-term debt, less current portion	53.4				57.0
Other noncurrent liabilities	10.9				7.5
Capital expenditures				(28.7)
Wireless Towers [Member] | Discontinued Operations [Member]
Deferred Gain on Sale of Property	$ 6.6				$ 13.1