Certain Balance Sheet Components



Accounts receivable, net	March 31, 2012		December 31, 2011
	(in thousands)
Trade receivables (net of allowance of $5,983 and $6,049)	$	335,633	$	328,845
Unbilled receivables	53,545		42,796
Total accounts receivable, net	$	389,178	$	371,641

At March 31, 2012 and December 31, 2011, $19.0 million and $2.5 million were recorded within trade receivables as billed but not yet paid by customers in accordance with contract retainage provisions. At March 31, 2012 and December 31, 2011, contract retainage amounts that were unbilled and classified as unbilled receivables were $9.2 million and $7.4 million. These contract retainage amounts within trade receivables and unbilled receivables are expected to be collected within the following 12 months.

At March 31, 2012, we had no long-term unbilled receivables or long-term retainage contract receivables as we expect to collect all contract retainage and unbilled receivables within the following 12 months. At December 31, 2011, long-term unbilled receivables and long-term retainage contracts totaled $31.5 million.



Allowance for doubtful account activity	Three Months Ended March 31,
	2012			2011
	(in thousands)
Beginning balance	$	6,049		$	9,045
Provision (release) of doubtful accounts, net	(60		)	(346		)
Accounts written-off	(239		)	(47		)
Effects of change in exchange rates	233			379
Ending balance	$	5,983		$	9,031



Inventories	March 31, 2012		December 31, 2011
	(in thousands)
Materials	$	115,069	$	112,470
Work in process	14,573		16,306
Finished goods	81,016		67,061
Total inventories	$	210,658	$	195,837

Our inventory levels may vary period to period as a result of our factory scheduling and the timing of contract fulfillments, which may include the buildup of finished goods for shipment.

Consigned inventory is held at third-party locations; however, we retain title to the inventory until purchased by the third-party. Consigned inventory, consisting of raw materials and finished goods, was $6.8 million and $7.4 million at March 31, 2012 and December 31, 2011, respectively.



Property, plant, and equipment, net	March 31, 2012			December 31, 2011
	(in thousands)
Machinery and equipment	$	276,719		$	269,611
Computers and purchased software	77,857			74,885
Buildings, furniture, and improvements	147,177			140,064
Land	28,632			26,126
Construction in progress, including purchased equipment	19,936			20,687
Total cost	550,321			531,373
Accumulated depreciation	(286,518		)	(268,703		)
Property, plant, and equipment, net	$	263,803		$	262,670



Depreciation expense	Three Months Ended March 31,
	2012		2011
	(in thousands)
Depreciation expense	$	15,314	$	15,934