Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Entity Vehicle Megabit Agency	Dec. 31, 2010
Capital expenditures anticipated [Abstract]
Range of capital expenditures anticipated for legacy and acquired properties - minimum	$ 625
Range of capital expenditures anticipated for legacy and acquired properties, maximum	675
Percentage of households in markets served to have broadband availability (in hundredths)	85.00%
Targeted minimum megabits per second in markets acquired by year 2013 (in Mbps)	3
Targeted minimum megabits per second in markets acquired by year 2015 (in Mbps)	4
Percentage of households throughout acquired Territories with broadband availability in excess of 1 Mbps (in hundredths)	87.00%
Percentage of households throughout acquired Territories with broadband availability in excess of 3 Mbps (in hundredths)	84.00%
Percentage of households throughout acquired Territories with broadband availability in excess of 4 Mbps (in hundredths)	80.00%
Number of state regulatory commissions requiring capital investment commitments	3
Aggregate amount placed into a cash escrow account for capital investment commitments required by state regulatory commissions		115.0
Escrow Deposit	42.7
Amount of letter of credit obtained for capital investment commitments required by state regulatory commissions		190
Letter Of Credit Reduced	20
Aggregate amount of cash in escrow accounts for service quality initiatives in the state of West Virginia	72.4
Cash balance in escrow accounts for service quality initiatives in the state of West Virginia	23.9
Liability associated with cash in escrow account for service quality initiatives in the state of West Virginia	0.2
Amount released from escrow	145.0
Recorded Unconditional Purchase Obligation, Fiscal Year Maturity Schedule [Abstract]
2013	132
2014	141.8
2015	140.8
Operating Leases [Abstract]
Number of vehicles accepted by the company for delivery	3,047
Additional expected number of vehicles to accept the delivery by next quarter	632
Percentage of expected vehicles to be leased under the program (in hundredths)	50.00%
Minimum lease commitment	1 year
Total annual lease expense for all new vehicles expected	30
Vermont Joint Owners consortium related commitments and contingencies [Abstract]
Number of utilities forming the Vermont Joint Owners consortium	14
Purchase power obligation (in hundredths)	10.00%
Number of years assumed if members of the consortium remained in default for the duration of the contract	3 years
Undiscounted purchase obligation if members of the consortium remained in default for the duration of the contract	$ 431.1