Accounts Payable and Accrued Liabilities - Components of Accounts Payable and Accrued Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Payables and Accruals [Abstract]
Accounts payable	$ 2,531	$ 1,726
Accrued network costs	1,146	1,169
Accrued taxes	3,938	3,959
Asset retirement obligations	410	358
Accrued outside services	993	1,049
Accrued accounting and legal	177	212
Accrued recognition awards	262	327
Accrued other	871	851
Deferred rent	77	77
Escheat liability	23	5
Lease incentive	168	152
Dividends payable - 2011 Long-Term Incentive Plan (LTIP)	567	0
Total accounts payable and accrued liabilities	$ 11,163	$ 9,885