Other Financial Information (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended
	Jan. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Other Current Assets
Prepaid expenses		$ 299	$ 257
Materials, supplies and inventory		162	125
Assets held for sale			96
Deferred activation and installation charges		62	53
Other		47	21
Total other current assets		570	552
Sale of wireless spectrum assets	43
Gain on sale of wireless spectrum assets	32
Reclassification of assets from held for sale to other intangible assets		53
Current liabilities
Accounts payable		1,285	1,207
Other current liabilities:
Accrued rent		46	48
Legal reserves		32	39
Unsettled repurchased common shares		18
Other		163	147
Total other current liabilities		259	234
Book overdraft balance		$ 237	$ 132