Intangibles (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Finite-Lived Intangible Assets [Line Items]
Total amortization expenses	$ 25,500,000	$ 17,900,000	$ 16,500,000
Capitalized Software Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Capitalized software development costs	12,600,000	16,500,000	13,300,000
Capitalized computer software amortization	13,400,000	10,700,000	9,100,000
Costs related to stock based compensation	$ 539,000	$ 719,000	$ 734,000
Useful life (in years)	3
Weighted-average useful lives (in years)	2.1
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum (in years)	10
Useful life, maximum (in years)	17
Weighted-average useful lives (in years)	6.9
Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average useful lives (in years)	2.6
Other Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted-average useful lives (in years)	2.4
Other Assets [Member] | Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life, minimum (in years)	3
Useful life, maximum (in years)	8