Accounts Receivable, Net (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts Receivable, Net [Abstract]
Total accounts receivable	$ 2,874us-gaap_AccountsReceivableGrossCurrent	$ 2,754us-gaap_AccountsReceivableGrossCurrent
Allowance for doubtful accounts	(68)	(69)
Total accounts receivable, net	2,806	2,685
U.S. Government Sales
Accounts Receivable, Net [Abstract]
Billed	536	596
Unbilled	6,806	5,801
Progress and performance-based payments received	(5,150)	(4,385)
Total accounts receivable	2,192	2,012
Other Customers
Accounts Receivable, Net [Abstract]
Billed	283	296
Unbilled	3,461	2,830
Progress and performance-based payments received	(3,062)	(2,384)
Total accounts receivable	$ 682	$ 742

Amount billed to customers under long-term contracts or programs but not paid. Excludes amounts due that have been withheld because of retainage provisions in a contract.

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Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business.

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A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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Amount of receivable reflecting the cost incurred on uncompleted contracts in excess of related billings.

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The amount of the offset related to government or other customer advances received on a contract when the expected advances will be applied in payment to those particular charges of the receivable.

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Amount to be collected within one year of the balance sheet date (or one operating cycle, if longer) from customers in accordance with the contractual provisions of long-term contracts or programs including amounts billed and unbilled as of the balance sheet date.

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