Acquisitions and Other Transactions Debt (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended				3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 6.000% Senior Notes due 2023 [Member]	Sep. 30, 2014 6.375% Senior Notes due 2025 [Member]	Dec. 31, 2014 Subsequent Event [Member] 7.875% Senior Notes due 2018 [Member]	Sep. 30, 2014 Product Financing Arrangement [Member]
Debt Instrument [Line Items]
Borrowing capacity						$ 108
Proceeds from issuance of short-term debt for purchases of inventory	100	0				100
Repayments of short-term debt for purchases of inventory	(514)	(194)				(100)
Handset financing, ending balance						0
Long-term debt issued, principal			1,300	1,700
Extinguishment of senior notes					$ 1,000