Schedule of Net Periodic Benefit Costs (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
FAS/CAS pension expense	$ 482	$ 830	$ 922

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