Long-Term Customer Financing And Sales Of Receivables (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 D	Dec. 31, 2011
Debt Instrument [Line Items]
Commitments to provide long-term financing	$ 47	$ 138
Allowance for uncollectable accounts, current	51	45
Allowance for uncollectable accounts, non-current	3	10
Long-term receivables	31	37
Servicing obligations for long-term receivables	317	263
Recourse obligation for sold account receivables	141
Receivables with past due balances greater than period reviewed for collectability, in days	90
Network Business [Member]
Debt Instrument [Line Items]
Allowance for uncollectable accounts		10
Sale Of NSN [Member]
Debt Instrument [Line Items]
Funded portion of the financing arrangements related to the Networks segment	110
Allowance for uncollectable accounts, current	7
Allowance for uncollectable accounts, non-current	3
Long-term receivables	$ 31