Organization and Significant Accounting Policies - Schedule of Estimated Useful Life of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2014
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 or lease term
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Minimum [Member] | Messaging devices [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	1 year
Minimum [Member] | Paging and computer equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	1 year
Minimum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Maximum [Member] | Messaging devices [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	2 years
Maximum [Member] | Paging and computer equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Maximum [Member] | Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years