Concentrations Of Risk (Schedule Of Major Customers, By Revenue Concentration) (Detail) (Segment, Continuing Operations [Member], Customer Concentration Risk [Member])	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Concentration Risk [Line Items]
Revenues as a percent of total	100.00%	100.00%	100.00%	100.00%
Top Ten Customers [Member]
Concentration Risk [Line Items]
Revenues as a percent of total	67.00%	73.00%	66.00%	73.00%
AT&T [Member]
Concentration Risk [Line Items]
Revenue from specific customers	17.00%	23.00%	17.00%	25.00%
DirectTV [Member]
Concentration Risk [Line Items]
Revenue from specific customers	16.00%	22.00%	17.00%	19.00%