Schedule Of Net Periodic Benefit Cost (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Non-cash FAS/CAS pension adjustment	$ (830)	$ (922)	$ (454)

This item represents the difference between pension expense or income calculated for financial reporting purposes under GAAP and pension costs calculated and funded in accordance with U.S. Government Cost Accounting Standards (CAS).

No definition available.

Name:	lmt_NonCashFasCasPensionAdjustment
Namespace Prefix:	lmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration