Summary of Significant Accounting Policies (Details Textuals) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Summary of Significant Accounting Policies (Textuals) [Abstract]
Amortization expense	$ 1.9	$ 1.5	$ 5.1	$ 4.6
Aggregate amortization expense, current			7.0
Aggregate amortization expense for 2012			7.4
Aggregate amortization expense for 2013			5.9
Aggregate amortization expense for 2014			5.8
Aggregate amortization expense for 2015			5.1
Aggregate amortization expense for 2016			4.9
Purchased intangible amortization, net of tax	1.1	2.9	0.9	2.7
Amortization expense associated with capitalized software	2.9	2.1	7.6	6.0
Standard Warranty Period	one		one
Share - based compensation expense	$ 3.1	$ 3.1	$ 8.8	$ 9.1