Significant Accounting Policies (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012 Method Source Project	Dec. 31, 2011 Project	Dec. 31, 2010	Dec. 31, 2009
Significant Accounting Policies [Line Items]
Inventory reserves	$ 30,426,000	$ 26,228,000	$ 24,948,000	$ 24,201,000
Impairments of long-lived assets	0	0	0
Number methods product revenue earn from company	2
Unbilled receivables	62,100,000	30,500,000
Percentage of total revenues	20.00%	20.00%
Percentage of product revenues	24.00%	23.00%
Number of projects	21	18
Number sources product revenue earn from company	3
Gains(losses) in foreign currency exchange transactions	$ (3,800,000)	$ (2,500,000)	$ 1,000,000