SUBSEQUENT EVENTS (Details) - Subsequent Event [Member] CAD in Millions, $ in Millions	Jan. 28, 2018 USD ($) mi	Jan. 18, 2018 CAD item mi	Jan. 18, 2018 USD ($) item mi
Optic Zoo Networks [Member]
Subsequent Event [Line Items]
Cash acquisition		CAD 31.0	$ 24.9
Acquired route miles added to fiber network		103	103
Optic Zoo Networks [Member] | Minimum
Subsequent Event [Line Items]
Number of on-net buildings connected | item		100	100
Neutral Path Communications And Near North Partners [Member]
Subsequent Event [Line Items]
Cash acquisition | $	$ 31.5
Acquired route miles added to fiber network	452