Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Information on Business Segments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
New business segments as a result of the reorganization
Segment Reporting Information [Line Items]
Number of business segments	2
Number of business segments as a result of the reorganization
Segment Reporting Information [Line Items]
Number of business segments	5
F-35 program \| Aeronautics
Segment Reporting Information [Line Items]
Program net sales as percent of total net sales	14.00%	13.00%	12.00%