Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jul. 31, 2012 TelWorx Communications LLC [Member]	Dec. 31, 2012 TelWorx Communications LLC [Member]	Dec. 31, 2012 TelWorx Communications LLC [Member]	Sep. 30, 2013 Minimum [Member]	Sep. 30, 2013 Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 161,000		$ 161,000		$ 161,000
Goodwill acquired						12,500,000
Goodwill impairment (TelWorx)						16,100,000	12,500,000	12,500,000
Amortization of intangible assets basis over estimated useful lives									1 year	8 years
Increase (decrease) in cost of intangible assets			(1,800,000)		(2,300,000)
Amortization of intangible assets	596,000	917,000	1,804,000	2,002,000	3,200,000
Impairment charges of intangible assets						1,000,000
Additional intangible assets acquired					$ 1,900,000