Summary Of Significant Accounting Policies (Research And Development Expenses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary Of Significant Accounting Policies [Line Items]
Total R&D	$ 1,212	$ 1,056	$ 925
Company-Sponsored R&D, Including Product Development Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Total R&D	372	325	360
Bid And Proposal Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Total R&D	173	183	160
Total Company-Sponsored R&D [Member]
Summary Of Significant Accounting Policies [Line Items]
Total R&D	545	508	520
Customer-Sponsored R&D [Member]
Summary Of Significant Accounting Policies [Line Items]
Total R&D	$ 667	$ 548	$ 405