Other Financial Information (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended
	Jan. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Other Current Assets
Prepaid expenses		$ 301	$ 257
Materials, supplies and inventory		134	125
Assets held for sale		53	96
Deferred activation and installation charges		59	53
Other		40	21
Total other current assets		587	552
Increase in other current assets		35
Prepayments		78
Sale of wireless spectrum assets	43
Gain on sale of wireless spectrum assets	32
Current liabilities
Accounts payable		1,094	1,207
Other current liabilities:
Accrued rent		47	48
Legal reserves		32	39
Other		195	147
Total other current liabilities		274	234
Book overdraft balance		$ 91	$ 132