Organization and Principles of Consolidation (Details) mi in Thousands	Jun. 30, 2016 state subscriptions mi
Product Information [Line Items]
Number of operating states | state	17
Communication Services
Product Information [Line Items]
Number of route miles in fiber network, more than | mi	21
Number of data subscribers	311,000
Communication Services | Maine, New Hampshire and Vermont
Product Information [Line Items]
Number of route miles in fiber network, more than | mi	17
Ethernet Circuits
Product Information [Line Items]
Number of data subscribers	15,100
Residential Voice Lines
Product Information [Line Items]
Number of data subscribers	389,000,000