Accounts Receivable (Tables)

12 Months Ended

Dec. 31, 2012

Accounts Receivable, Net [Abstract]

Accounts Receivable

Accounts receivable represent amounts billed and currently due from customers and consisted of the following:

December 31	2011		2012
Non-U.S. government	$	2,536	$	2,728
U.S. government	1,039		778
Commercial	854		698
Total accounts receivable	$	4,429	$	4,204