Discontinued Operations - Summary of Cash Flow Related to Discontinued Operations (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net cash provided by discontinued operating activities	$ 4,733	$ 17,094
Net cash used in discontinued investing activities	(556)	(488)
Wireless Network Deployment and Wireline Businesses
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net cash provided by discontinued operating activities	4,733	17,094
Net cash used in discontinued investing activities	$ (556)	$ (488)