Intangibles (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Finite-Lived Intangible Assets [Line Items]
Total intangible assets amortization expenses	$ 7,300,000	$ 6,800,000	$ 21,000,000	$ 17,500,000
Capitalized Software Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Capitalized software development costs	1,700,000	2,100,000	11,800,000	11,900,000
Capitalized computer software amortization	3,500,000	3,300,000	10,600,000	9,900,000
Costs related to stock based compensation	$ 89,000	$ 96,000	$ 489,000	$ 508,000
Useful life (in years)			3 years
Minimum [Member] | Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)			3 years
Minimum [Member] | Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)			10 years
Maximum [Member] | Acquired Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)			8 years
Maximum [Member] | Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life (in years)			17 years