Accounts Payable and Accrued Liabilities - Components of Accounts Payable and Accrued Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accounts payable	$ 1,215	$ 2,784
Accrued network costs	1,059	1,072
Accrued taxes	4,533	4,195
Asset retirement obligations	376	342
Accrued outside services	1,016	1,101
Accrued accounting and legal	253	275
Accrued recognition awards	321	345
Accrued other	709	696
Deferred rent	77	77
Escheat liability	38	0
Lease incentive	40	147
Dividends payable - 2011 Long-Term Incentive Plan (LTIP)	0	637
Capital lease payable	16	17
Total accounts payable and accrued liabilities	$ 9,653	$ 11,688