Segment Information - Assets by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,442,999	$ 1,484,407
Operating Segments | Wireless
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,039,531	1,101,716
Operating Segments | Cable
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	225,954	218,471
Operating Segments | Wireline
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	123,123	115,282
Operating Segments | Other
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 54,391	$ 48,938