Legal Proceedings (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 A-12 Program [Member]	Dec. 31, 2011 A-12 Program [Member]	Dec. 31, 2012 A-12 Program [Member] Unliquidated Progress Payments [Member]	Dec. 29, 2009 A-12 Program [Member] Unliquidated Progress Payments [Member]	Dec. 31, 2012 A-12 Program [Member] Program Termination [Member]	Dec. 31, 2012 A-12 Program [Member] Interest On Unliquidated Progress Payments [Member]
Legal Proceedings [Line Items]
Long-term contracts in progress, Gross	$ 15,130	$ 13,587	$ 587
Inventory Valuation Reserves			350
Loss contingency, estimate of possible loss			1,741		1,350	1,352	275	1,585
Inventory subject to uncertainty			237	236
Unrecorded gain contingency			$ 1,187