Property and Equipment (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment
Property and equipment, gross	$ 4,370	$ 4,142
Less: accumulated depreciation	(1,296)	(1,260)
Property and equipment, net	3,074	2,882
Network equipment
Property, Plant and Equipment
Property and equipment, gross	2,444	2,351
Land
Property, Plant and Equipment
Property and equipment, gross	45	45
Buildings
Property, Plant and Equipment
Property and equipment, gross	1,076	1,071
Leasehold improvements
Property, Plant and Equipment
Property and equipment, gross	214	203
Computer software, office equipment and other
Property, Plant and Equipment
Property and equipment, gross	104	95
Construction in progress
Property, Plant and Equipment
Property and equipment, gross	$ 487	$ 377