Business Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Number of Operating Segments	3		4
Investment in CyrusOne	$ 290.7			$ 290.7		$ 471.0
Proceeds from Sales of Business, Affiliate and Productive Assets	210
Revenue	319.9	312.0		642.4	637.7
Operating income	35.6	46.8		92.5	66.0
Expenditures for long-lived assets	41.2	45.0		75.5	95.9
Depreciation and amortization	60.3	37.2		107.2	87.8
Assets	2,176.9			2,176.9		2,107.3
Wireline [Member]
Segment Reporting Information [Line Items]
Revenue	184.7	181.6		368.3	361.3
Operating income	50.5	48.9		103.1	99.0
Expenditures for long-lived assets	38.1	39.3		64.3	73.1
Depreciation and amortization	28.2	27.3		56.3	54.1
Assets	791.2			791.2		780.8
IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenue	101.6	86.0		203.5	170.5
Operating income	2.8	0.3		8.2	2.2
Expenditures for long-lived assets	2.5	3.7		5.0	4.9
Depreciation and amortization	2.8	2.5		5.6	5.0
Assets	46.6			46.6		48.9
Wireless [Member]
Segment Reporting Information [Line Items]
Proceeds from Sales of Business, Affiliate and Productive Assets	210
Prepaid Lifeline Subscribers	21,300			21,300
Revenue	41.2	51.7		85.9	105.0
Operating income	(13.1)	11.4		(7.8)	12.1
Expenditures for long-lived assets	0.6	2.0		6.2	10.2
Depreciation and amortization	29.3	7.3		45.1	23.3
Assets	202.9			202.9		247.5
Data Center Colocation [Member]
Segment Reporting Information [Line Items]
Revenue	0	0		0	15.6
Operating income	0	0		0	3.2
Expenditures for long-lived assets	0	0		0	7.7
Depreciation and amortization	0	0		0	5.2
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income	(4.6)	(13.8)		(11.0)	(50.5)
Depreciation and amortization	0	0.1		0.2	0.2
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(7.6)	(7.3)		(15.3)	(14.7)
Intersegment Eliminations [Member] | Wireline [Member]
Segment Reporting Information [Line Items]
Revenue	4.0	4.2		8.1	8.6
Intersegment Eliminations [Member] | IT Services and Hardware [Member]
Segment Reporting Information [Line Items]
Revenue	3.0	2.5		6.1	4.5
Intersegment Eliminations [Member] | Wireless [Member]
Segment Reporting Information [Line Items]
Revenue	0.6	0.6		1.1	1.2
Intersegment Eliminations [Member] | Data Center Colocation [Member]
Segment Reporting Information [Line Items]
Revenue	0	0		0	0.4
Intersegment Eliminations [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Assets	1,136.2			1,136.2		1,030.1
Sales [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	7.6	7.3		15.3	14.7
Prepaid Lifeline Subscribers [Member] | Wireless [Member]
Segment Reporting Information [Line Items]
Revenue				$ 5.0