Property and Equipment (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment
Property and equipment, gross	$ 3,273	$ 1,925
Accumulated depreciation	(882)	(450)
Property and equipment, net	2,391	1,475
Depreciation expense	566	303	129
Assets acquired under capital lease agreements	1,280	881
Accumulated depreciation of property and equipment acquired under capital leases	437	210
Network Equipment
Property, Plant and Equipment
Property and equipment, gross	1,912	1,016
Land
Property, Plant and Equipment
Property and equipment, gross	36	34
Buildings
Property, Plant and Equipment
Property and equipment, gross	594	355
Leasehold Improvements
Property, Plant and Equipment
Property and equipment, gross	194	120
Computer software, office equipment and other
Property, Plant and Equipment
Property and equipment, gross	93	73
Construction in progress
Property, Plant and Equipment
Property and equipment, gross	$ 444	$ 327