Acquisition of TelWorx Communications LLC - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Jul. 31, 2012	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2012	Sep. 30, 2013	Dec. 31, 2012	Mar. 31, 2013	Oct. 31, 2012
Business Acquisition [Line Items]
Legal settlement date					Mar. 27, 2013
Reduction in total combined earnings			$ 0.2	$ 0.4
Forensic audit dollar coverage percentage of operation's revenue					50.00%
TelWorx Communications LLC [Member]
Business Acquisition [Line Items]
Purchase price acquisition, fair value					16.1
Cash paid					16.0
Contingent consideration related to claims escrow					1.1
Potential earn-out at fair value							1.0
Goodwill impairment	16.1	12.5				12.5
Business acquisition estimated annual sales of acquired entity		18.5				18.5
Business acquisition estimated gross profit of acquired entity		3.2				3.2
Business acquisition estimated revenue gross profit percentage		18.00%				18.00%
Business acquisition estimated sales funnel conversion to actual sales percentage								50.00%
Business acquisition estimated first quarter sales funnel of acquired entity								7.5
Percentage of reduction in project revenue due to impairment of goodwill								17.00%
Reduction in total combined earnings			0.1	0.5
TelWorx Communications LLC [Member] | Goodwill [Member]
Business Acquisition [Line Items]
Goodwill		12.5				12.5
TelWorx Communications LLC [Member] | Backlog [Member]
Business Acquisition [Line Items]
Business acquisition estimated first quarter sales of acquired entity								1.0
TelWorx Communications LLC [Member] | Backlog And Funnel [Member]
Business Acquisition [Line Items]
Business acquisition estimated revenue gross profit percentage								16.00%
TelWorx Communications LLC [Member] | After Devaluation [Member]
Business Acquisition [Line Items]
Business acquisition estimated annual sales of acquired entity								15.0
Business acquisition estimated revenue gross profit percentage								16.00%
TelWorx Communications LLC [Member] | Estimated Fair Value [Member] | Goodwill [Member]
Business Acquisition [Line Items]
Goodwill		9.5				9.5
TelWorx Communications LLC [Member] | Provisional Adjustments [Member] | Goodwill [Member]
Business Acquisition [Line Items]
Goodwill		$ 3.1				$ 3.1
TelWorx Communications LLC [Member] | Lexington, North Carolina [Member]
Business Acquisition [Line Items]
Period for continued use of operating facility					5 years
Lease effective date					Aug. 01, 2013
TelWorx Communications LLC [Member] | Pryor, Oklahoma [Member]
Business Acquisition [Line Items]
Period for continued use of operating facility					2 years