Commitments and Contingencies - Schedule of Significant Customers, Revenue Concentration Information (Details) - Sales Revenue Net - Customer Concentration Risk	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Concentration Risk [Line Items]
Percentage of revenue	88.60%	89.40%	89.90%	86.20%
Subsidiaries of AT&T Inc.
Concentration Risk [Line Items]
Percentage of revenue	45.00%	70.70%	56.30%	65.70%
DIRECTV
Concentration Risk [Line Items]
Percentage of revenue	43.60%	18.70%	33.60%	20.50%
Other
Concentration Risk [Line Items]
Percentage of revenue	11.10%	10.60%	10.10%	13.80%