Accounts Receivable, Net (Tables)

12 Months Ended

Dec. 31, 2011

ACCOUNTS RECEIVABLE, NET [Abstract]

Accounts receivable

	December 31
$ in millions	2011				2010
Due From U.S. Government
Amounts billed		$	812			$	900
Recoverable costs and accrued profit on progress completed - unbilled			1,594				1,718
			2,406				2,618
Due From Other Customers
Amounts billed			249				280
Recoverable costs and accrued profit on progress completed - unbilled			363				458
			612				738
Total accounts receivable			3,018				3,356
Allowance for doubtful accounts			(54	)			(27	)
Total accounts receivable, net		$	2,964			$	3,329