Accounts Receivable, Net

12 Months Ended

Dec. 31, 2016

Receivables [Abstract]

Accounts Receivable, Net

4. ACCOUNTS RECEIVABLE, NET

Unbilled amounts represent sales for which billings have not been presented to customers by period-end. These amounts are usually billed and collected within one year. Substantially all accounts receivable at December 31, 2016 are expected to be collected in 2017. The company does not believe it has significant exposure to credit risk, as accounts receivable and the related unbilled amounts are primarily due from the U.S. Government either as the ultimate customer or in connection with foreign military sales. Progress and performance-based payments are reflected as an offset to the related unbilled accounts receivable balance for contracts accounted for under the cost-to-cost method of percentage-of-completion accounting.

Accounts receivable consisted of the following:

	December 31
$ in millions	2016			2015
Due from U.S. Government
Billed	$	444		$	506
Unbilled	8,878			7,699
Progress and performance-based payments received	(7,123		)	(6,140		)
	2,199			2,065
Due from International and Other Customers(1)
Billed	238			223
Unbilled	4,747			3,713
Progress and performance-based payments received	(3,822		)	(3,101		)
	1,163			835
Total accounts receivable	3,362			2,900
Allowance for doubtful accounts	(63		)	(59		)
Total accounts receivable, net	$	3,299		$	2,841

⁽¹⁾  Includes receivables due from the U.S. Government associated with foreign military sales.