Long-Lived Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Depreciation, amortization and accretion expense	$ 15,167,000	$ 18,232,000	$ 19,334,000
Change in accounting estimate will reduce depreciation expense	100,000
Reduction in asset retirement cost	(131,000)	(386,000)
Asset retirement costs partially offset in fully depreciated asset retirement costs	9,664,000	11,054,000	13,253,000
Other long-term liabilities	9,259,000	9,789,000
Percentage of fair value estimate of contractor fees escalation by each year	4.00%
Long term cost associated with estimated removal costs	9,600,000
Accretion expense on the asset retirement obligation liabilities	538,000	767,000	807,000
Accretion expense on the asset retirement obligation liabilities	567,000	738,000
Impairment charge of intangible assets	0	3,382,000	0
Amortizable intangible assets, gross carrying amount	41,526,000	41,956,000
Amortizable intangible assets, accumulated amortization	16,158,000	11,623,000
Goodwill	133,031,000	133,031,000
Impairment of long-lived assets	0	0	0
Paging equipment assets [Member]
Finite-Lived Intangible Assets [Line Items]
Depreciation, amortization and accretion expense	1,000,000	1,100,000
Capitalized Costs, Asset Retirement Costs	3,800,000	1,700,000
Asset retirement obligation liability [Member]
Finite-Lived Intangible Assets [Line Items]
Accrued other liabilities	400,000	400,000
Costs of deconstructing assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other long-term liabilities	7,600,000	7,600,000
Other intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Accretion expense on the asset retirement obligation liabilities	600,000	700,000	800,000
Amortization expense for other intangible assets	5,000,000	6,400,000	5,300,000
Wireless Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Depreciation, amortization and accretion expense	9,600,000	11,200,000	14,000,000
Amortizable intangible assets, gross carrying amount	0	400,000
Amortizable intangible assets, accumulated amortization		300,000
Wireless Operations [Member] | Paging and computer equipment [Member]
Finite-Lived Intangible Assets [Line Items]
Depreciation expenses	1,100,000	1,900,000	3,300,000
Software Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Depreciation, amortization and accretion expense	5,600,000	7,000,000	5,300,000
Accretion expense on the asset retirement obligation liabilities	(29,000,000)	29,000,000
Impairment charge of intangible assets	0	3,400,000	0
Amortizable intangible assets, gross carrying amount	41,500,000	41,500,000
Amortizable intangible assets, accumulated amortization	16,200,000	11,300,000
Goodwill	133,000,000	133,000,000
Software Operations [Member] | Computer equipment and leasehold improvements [Member]
Finite-Lived Intangible Assets [Line Items]
Depreciation expenses	800,000	800,000	300,000
Minimum [Member] | Paging equipment assets [Member]
Finite-Lived Intangible Assets [Line Items]
Equipment assets estimated useful life	12 months
Minimum [Member] | Software Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	2 years
Maximum [Member] | Paging equipment assets [Member]
Finite-Lived Intangible Assets [Line Items]
Equipment assets estimated useful life	60 months
Maximum [Member] | Software Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	15 years
Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross carrying amount	2,370,000	2,800,000
Amortizable intangible assets, accumulated amortization	$ 2,132,000	$ 2,431,000
Non-compete agreements [Member] | Wireless Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	3 years
Non-compete agreements [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	3 years
Non-compete agreements [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, Useful Life	5 years