Receivables

12 Months Ended

Dec. 31, 2011

Receivables [Abstract]

Receivables

(2)  Receivables

The components of receivables as of December 31, 2011 and 2010 were as follows (in thousands):        

	2011		2010
Billed	$	48,382	$	40,494
Unbilled (principally December work billed in January)		69,186		116,444
Total receivables, net	$	117,568	$	156,938

The unbilled balance includes certain costs for work performed at risk but which we believe will be funded by the government totaling approximately $5.5 million and $4.2 million as of December 31, 2011, and 2010, respectively. We expect to invoice substantially all unbilled receivables during 2012.