Business Segment Information (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting [Abstract]
Revenue	$ 308,400,000	$ 310,800,000	$ 312,000,000	$ 325,700,000	$ 374,700,000	$ 368,200,000	$ 368,200,000	$ 362,800,000	$ 1,256,900,000	$ 1,473,900,000	$ 1,462,400,000
Operating income (loss)	40,100,000	57,700,000	46,800,000	19,200,000	57,900,000	66,000,000	65,200,000	81,000,000	163,800,000	270,100,000	259,500,000
Expenditures for long-lived assets									(196,900,000)	(367,200,000)	(255,500,000)
Depreciation and amortization									169,600,000	217,400,000	199,500,000
Assets	2,107,300,000				2,872,400,000				2,107,300,000	2,872,400,000
Service revenue									1,039,300,000	1,272,800,000	1,250,800,000
Product revenue									217,600,000	201,100,000	211,600,000
Segment Reporting Information, Additional Information [Abstract]
Number of Operating Segments	3			4
Restructuring charges									13,700,000	3,400,000	12,200,000
Curtailment (gain) loss									(600,000)	0	4,200,000
Loss (gain) on sale of assets									2,400,000	(1,600,000)	(8,400,000)
Impairment of assets, excluding goodwill									0	(14,200,000)	(2,100,000)
Impairment of goodwill									0	0	50,300,000
Loss from CyrusOne equity method investment									(10,700,000)	0	0
Investment in CyrusOne	471,000,000				0				471,000,000	0
Asset Impairment Charges									0	14,200,000	52,400,000
Transaction-related compensation									42,600,000	0	0
Transaction costs									1,600,000	6,300,000	2,600,000
Handsets and accessories [Member]
Segment Reporting [Abstract]
Product revenue									21,800,000	23,200,000	30,300,000
IT, telephony and other equipment [Member]
Segment Reporting [Abstract]
Product revenue									195,800,000	177,900,000	181,300,000
Wireline [Member]
Segment Reporting [Abstract]
Revenue									724,800,000	730,500,000	732,100,000
Operating income (loss)									190,200,000	212,900,000	228,500,000
Expenditures for long-lived assets									(162,600,000)	(114,200,000)	(112,600,000)
Depreciation and amortization									112,200,000	106,000,000	102,400,000
Assets	780,800,000				723,700,000				780,800,000	723,700,000
Service revenue									702,300,000	705,000,000	703,300,000
Segment Reporting Information, Additional Information [Abstract]
Restructuring charges									9,100,000	3,500,000	7,700,000
Curtailment (gain) loss									(600,000)		4,200,000
Loss (gain) on sale of assets									(1,100,000)	(1,800,000)	(8,400,000)
Impairment of assets, excluding goodwill									0	500,000	1,000,000
Impairment of goodwill										0
Wireless [Member]
Segment Reporting [Abstract]
Revenue									201,500,000	241,800,000	277,600,000
Operating income (loss)									18,200,000	51,200,000	3,300,000
Expenditures for long-lived assets									(16,000,000)	(15,800,000)	(17,600,000)
Depreciation and amortization									41,200,000	31,900,000	33,500,000
Assets	247,500,000				275,600,000				247,500,000	275,600,000
Service revenue									183,100,000	222,700,000	250,800,000
Segment Reporting Information, Additional Information [Abstract]
Restructuring charges									200,000	1,600,000	0
Loss (gain) on sale of assets									3,500,000
Impairment of assets, excluding goodwill									0	400,000	1,100,000
Impairment of goodwill										0	50,300,000
IT Services and Hardware [Member]
Segment Reporting [Abstract]
Revenue									344,100,000	315,700,000	300,500,000
Operating income (loss)									8,500,000	10,300,000	9,800,000
Expenditures for long-lived assets									(10,600,000)	(9,000,000)	(6,800,000)
Depreciation and amortization									10,500,000	8,600,000	8,400,000
Assets	48,900,000				43,300,000				48,900,000	43,300,000
Service revenue									138,700,000	130,200,000	114,100,000
Segment Reporting Information, Additional Information [Abstract]
Restructuring charges									700,000	(1,200,000)	1,900,000
Impairment of goodwill										0
Data Center Colocation [Member]
Segment Reporting [Abstract]
Revenue									15,600,000	221,300,000	184,700,000
Operating income (loss)									3,200,000	30,400,000	46,400,000
Expenditures for long-lived assets									(7,700,000)	(228,200,000)	(118,500,000)
Depreciation and amortization									5,200,000	70,600,000	54,800,000
Assets	0				1,208,500,000				0	1,208,500,000
Service revenue									15,200,000	214,900,000	182,600,000
Segment Reporting Information, Additional Information [Abstract]
Restructuring charges									0	500,000	0
Loss (gain) on sale of assets										(200,000)
Impairment of assets, excluding goodwill										11,800,000
Impairment of goodwill										0
Asset Impairment Charges										13,300,000
Corporate Segment [Member]
Segment Reporting [Abstract]
Operating income (loss)									(56,300,000)	(34,700,000)	(28,500,000)
Depreciation and amortization									500,000	300,000	400,000
Segment Reporting Information, Additional Information [Abstract]
Restructuring charges									3,700,000	(1,000,000)	2,600,000
Transaction costs									1,600,000	6,300,000	2,600,000
Intersegment Eliminations [Member]
Segment Reporting [Abstract]
Revenue									(29,100,000)	(35,400,000)	(32,500,000)
Intersegment Eliminations [Member] | Wireline [Member]
Segment Reporting [Abstract]
Revenue									16,800,000	19,100,000	23,000,000
Intersegment Eliminations [Member] | Wireless [Member]
Segment Reporting [Abstract]
Revenue									2,300,000	2,300,000	2,300,000
Intersegment Eliminations [Member] | IT Services and Hardware [Member]
Segment Reporting [Abstract]
Revenue									9,600,000	7,600,000	5,100,000
Intersegment Eliminations [Member] | Data Center Colocation [Member]
Segment Reporting [Abstract]
Revenue									400,000	6,400,000	2,100,000
Intersegment Eliminations [Member] | Corporate Segment [Member]
Segment Reporting [Abstract]
Assets	1,030,100,000				621,300,000				1,030,100,000	621,300,000
Sales [Member] | Intersegment Eliminations [Member]
Segment Reporting [Abstract]
Revenue									$ 29,100,000	$ 35,400,000	$ 32,500,000