Property, Plant And Equipment (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property, Plant And Equipment [Abstract]
Depreciation	$ 11,451,000	$ 11,261,000	$ 9,648,000
Depreciation expense for capitalized computer software costs	4,100,000	3,900,000	3,700,000
Unamortized computer software costs	$ 13,800,000	$ 11,400,000