Inventories, net (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Inventories, net
Raw materials	$ 65,550,000		$ 72,013,000
Work in process	17,139,000		12,253,000
Finished goods (completed systems)	16,040,000		15,968,000
Inventories, net	98,729,000		100,234,000
Inventory reserves	35,300,000		33,600,000
Inventories, net
Cost of sales due to below normal production capacity	500,000	0
Dry strip product line, intellectual property rights and certain assets
Inventories, net
Cost of sales due to non-recoverable inventory components	$ 2,100,000
Size of dry strip wafer equipment and products, Company license to make and sell (in millimeters)	300