Basis of Presentation (Unaudited) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Changes in contract estimates, increase in earnings from continuing operations	$ 197,000,000	$ 174,000,000
Changes in contract estimates, increase in earnings from continuing operations, per diluted share	$ 0.58	$ 0.47
Current period impact of reclassification	126,000,000
Prior period reclassification adjustment			277,000,000
Accumulated Other Comprehensive Loss
Unamortized benefit plan costs, net of tax benefit of $1,933 as of March 31, 2014 and $1,972 as of December 31, 2013	(2,939,000,000)		(3,000,000,000)
Cumulative translation adjustment	20,000,000		18,000,000
Net unrealized loss on marketable securities and cash flow hedges, net of tax benefit	(2,000,000)		(2,000,000)
Total accumulated other comprehensive loss	(2,921,000,000)		(2,984,000,000)
Unamortized benefit plan costs - Tax Benefit (expense)	1,933,000,000		1,972,000,000
Unamortized benefit plan costs, net actuarial losses, after-tax	3,200,000,000		3,300,000,000
Unamortized benefit plan costs, reclassified from other comprehensive income to net earnings	$ 38,000,000	$ 80,000,000