Summary of Significant Accounting Policies (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Summary of Significant Accounting Policies (Textuals) [Abstract]
Amortization expense	$ 1.9	$ 1.5
Aggregate amortization expense, current	7.2
Aggregate amortization expense for 2012	5.9
Aggregate amortization expense for 2013	5.8
Aggregate amortization expense for 2014	5.1
Aggregate amortization expense for 2015	4.9
Aggregate amortization expense for 2016	4.7
Purchased intangible amortization, net of tax	1.1	0.9
Amortization expense associated with capitalized software	3.2	2.1
Standard Warranty Period	one
Share - based compensation expense	$ 3.3	$ 3.2