Accounts Receivable, Net (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Accounts Receivable [Member]		Mar. 31, 2013 Accounts Receivable [Member]
Receivables [Abstract]
Amounts billed or billable	$ 2,772	$ 2,651
Unbilled amounts	364	390
Allowance for doubtful accounts	(104)	(112)
Accounts Receivable, Net	3,032	2,929
Billable contracts receivable to be invoiced in the subsequent month	1,049	1,054
Accounts Receivable Sales Arrangements [Abstract]
Deferred proceeds receivables from sales of accounts receivables	125	121
Remaining account receivable sold and derecognized	736	723
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable sales			822		854
Deferred proceeds			124		115
Loss on sales of accounts receivable			4		4
Estimated Decrease to Operating Cash Flows			$ 11	[1]	$ 16	[1]

[1] Represents the difference between current and prior period receivable sales adjusted for the effects of: (i) the deferred proceeds, (ii) collections prior to the end of the quarter and (iii) currency.