Summary of Significant Accounting Policies (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2011	Dec. 31, 2011 Segment	Dec. 31, 2010	Dec. 31, 2009
Summary of Significant Accounting Policies (Amounts in paragraphs)
Number of operating segments		4
Research and development expenses		$ 543	$ 580	$ 588
Accrued receivables related to insurance reimbursements		0	0
Outsourcing contract costs - Additions		4	4	57
Outsourcing contract costs - Amortization		45	39	46
Outsourcing contract costs - Deferred Balance		198	239
Aggregate net changes in contract estimates leading Increase in earnings from continuing operations		738	675	421
Aggregate net changes in contract estimates leading Increase in earnings from continuing operations per diluted share		$ 1.70	$ 1.46	$ 0.85
Original maturity period of highly liquid instruments		three months or less
Change in unamortized benefit plan costs, net of tax		(1,249)	297	561
Change in accumulated other comprehensive loss	(524)
Net after tax actuarial loss		3,900	2,800
Accumulated Other Comprehensive Loss
Cumulative translation adjustment		(4)	0
Net unrealized gain on marketable securities and cash flow hedges, net of tax expense of $ 0 as of December 31 2011, and $3 as of December 31, 2010		1	5
Unamortized benefit plan costs, net of tax benefit of $ 2289 as of December 31 2011 and $1,801 as of December 31, 2010		(3,487)	(2,762)
Total accumulated other comprehensive loss		(3,490)	(2,757)
Accumulated Other Comprehensive Loss (Parenthetical)
Tax expense on net unrealized gain on marketable securities and cash flow hedges		0	3
Tax benefit on unamortized benefit plan costs		$ 2,289	$ 1,801
Accumulated Other Comprehensive Loss (Amounts in paragraphs)
Percentage threshold for excess gains or losses that are subject to amortization		10.00%
Average future service period of employees		10 years
Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and stock awards (years)		3 to 4 years
Stock Awards Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options and stock awards (years)		3 to 5 years
Land Improvements
Property, Plant and Equipment [Line Items]
Useful Life, Minimum		2
Useful Life, Maximum		40
Buildings and improvements
Property, Plant and Equipment [Line Items]
Useful Life, Minimum		2
Useful Life, Maximum		45
Machinery and other equipment
Property, Plant and Equipment [Line Items]
Useful Life, Minimum		2
Useful Life, Maximum		20
Capitalized software costs
Property, Plant and Equipment [Line Items]
Useful Life, Minimum		3
Useful Life, Maximum		5
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives		Length of lease