Discontinued Operations - Summary of Financial Results Related to Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net income (loss) from discontinued operations	$ (723)	$ 9,435	$ (1,551)	$ 11,176
Wireless Network Deployment and Wireline Businesses
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Revenues	42,501	105,507	85,396	239,048
Cost of revenues	38,939	91,502	76,789	216,717
Gross profit (exclusive of depreciation and amortization included in selling, general and administrative expense shown below)	3,562	14,005	8,607	22,331
Selling, general and administrative expenses	3,797	4,125	8,916	9,099
Restructuring expense	479	409	940	1,366
Impairment expense			281	633
Operating income (loss)	(714)	9,471	(1,530)	11,233
Loss before income taxes	(714)	9,471	(1,530)	11,233
Income (loss) tax expense	9	36	21	57
Net income (loss) from discontinued operations	$ (723)	$ 9,435	$ (1,551)	$ 11,176