Inventories (Details) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Inventories, net of reserves [Abstract]
Raw materials and parts	$ 117,114,000	$ 96,731,000
Work-in-process	72,066,000	60,463,000
Finished goods	76,960,000	77,583,000
Used equipment	15,012,000	18,204,000
Total	281,152,000	252,981,000
Inventory reserves	$ 20,495,000	$ 19,399,000