Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Apr. 01, 2015	Dec. 31, 2014
Proceeds from Sale of Intangible Assets			$ 194.4
Indefinite-Lived Intangible Assets (Excluding Goodwill)			88.2
Gain on Liabilities and Other Assets transferred in Sale of Business Affiliate and Productive Assets	$ (15.9)				$ (15.9)	$ 0.0
Property, plant and equipment, net	894.5				894.5			$ 815.4
Current portion of long-term debt	12.5				12.5			11.6
Selling, General and Administrative Expense	57.0			$ 49.5	109.2	98.8
Depreciation and amortization	34.0			31.0	66.6	62.1
Restructuring charges	2.3	$ 3.4		1.2	5.7	1.2
Amortization of deferred gain					6.5	10.1
Operating income	29.7			47.3	66.8	97.7
Other Nonoperating Income (Expense)	0.0			0.9	(0.4)	1.2
Gain on sale of wireless spectrum licenses					(112.6)	0.0
Other noncurrent liabilities	39.1				39.1			26.2
Prepaid Expense, Current	13.8				13.8			10.8
Income tax expense (benefit)	101.4			75.4	102.0	81.9
Net income	191.6			114.2	240.8	121.2
Disposal Group, Including Discontinued Operation, Other Assets, Current	1.6				1.6			4.7
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	0.0				0.0			44.6
Restructuring Reserve, Current	2.4				2.4			4.9
Other current liabilities from discontinued operations	19.8				19.8			142.0
Restructuring Reserve, Noncurrent	0.2				0.2
Other noncurrent liabilities from discontinued operations	2.1				2.1			102.7
Liabilities	1,913.1				1,913.1			2,469.2
Payments for Restructuring	(3.5)	(4.5)
Payments to Acquire Property, Plant, and Equipment	74.6			40.6	132.5	75.5
Continuing Operations [Member]
Long-term Debt, Current Maturities	1.1				1.1			1.1
Long-term Debt, Excluding Current Maturities	52.8				52.8			57.0
Other noncurrent liabilities	9.4				9.4			7.5
Net income	180.7			123.7	181.0	129.6
Liabilities	63.3				63.3			65.6
Payments to Acquire Property, Plant, and Equipment						69.3
Discontinued Operations [Member]
Gain on Liabilities and Other Assets transferred in Sale of Business Affiliate and Productive Assets	(15.9)			0.0	15.9	0.0
Property, plant and equipment, net							$ 16.0
Current portion of long-term debt							0.5
Long-term debt, less current portion							24.8
Other non-current liabilities	0.0				0.0		6.6	8.0
Total Liabilities	21.9				21.9		$ 31.9	244.7
Revenue	0.0			41.2	4.4	85.9
Cost of products and services	0.0			19.7	12.0	39.5
Selling, General and Administrative Expense	0.9			5.2	2.2	11.4
Depreciation and amortization	0.0			29.3	28.6	45.1
Restructuring charges	0.0			5.2	6.4	5.2
Amortization of deferred gain	0.0			(6.5)	(6.5)	(10.1)
Operating Costs and Expenses	0.9			52.9	42.7	91.1
Operating income	(0.9)			(11.7)	(38.3)	(5.2)
Interest Income (Expense), Net	(0.9)			1.2	(1.7)	2.7
Other Nonoperating Income (Expense)	(0.1)			1.0	(0.1)	1.9
Gain on sale of wireless spectrum licenses	0.0	$ (112.6)		0.0	112.6	0.0
Long-term Debt, Current Maturities	0.0				0.0			1.6
Long-term Debt, Excluding Current Maturities	0.0				0.0			81.6
Prepaid Expense, Current	0.0		$ 6.4		0.0			3.2
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	16.0			(13.9)	92.0	(9.8)
Income tax expense (benefit)	5.1			(4.4)	32.2	(1.4)
Net income	10.9			$ (9.5)	59.8	(8.4)
Disposal Group, Including Discontinued Operation, Other Assets, Current	1.6				1.6			1.5
Disposal Group, Including Discontinued Operation, Assets, Current	1.6				1.6			4.7
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	0.0				0.0			44.1
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	0.0				0.0			0.5
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0.0				0.0			44.6
Disposal Group, Including Discontinued Operation, Assets	1.6				1.6			49.3
Restructuring Reserve, Current	14.1				14.1			15.4
Accounts Payable	2.0				2.0			5.0
Deferred Gain on Sale of Property	0.0				0.0			112.6
Other current liabilities from discontinued operations	3.7				3.7			7.4
Disposal Group, Including Discontinued Operation, Liabilities, Current	19.8				19.8			142.0
Restructuring Reserve, Noncurrent	2.1				2.1			0.0
Other noncurrent liabilities from discontinued operations	2.1				2.1			102.7
Increase (Decrease) in Prepaid Rent					3.2	0.0
Payments for Restructuring					(6.0)	(0.6)
Payments to Acquire Property, Plant, and Equipment					0.0	$ (6.2)
Wireless Towers [Member] | Discontinued Operations [Member]
Deferred Gain on Sale of Property	$ 0.0				$ 0.0			$ 13.1