Summary Of Goodwill & Intangible Assets (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Intangible Assets [Line Items]
Gross Carrying Amount, Finite-Lived Intangible Assets	$ 128,170,000		$ 106,258,000
Accumulated Amortization, Finite-Lived Intangible Assets	(61,982,000)		(49,169,000)
Net Carrying Amount, Finite-Lived Intangible Assets	66,188,000		57,089,000
Indefinite lived intangible assets	102,000		113,000
Goodwill	2,791,000		2,729,000
Gross Carrying Amount, Total Intangible Assets	131,063,000		109,100,000
Net Carrying Amount, Total Intangible Assets	69,081,000		59,931,000
Gross Capitalized Software Held Under Capital Lease	4,100,000		4,100,000
Amortization of Capitalized Software Held Under Capital Lease	1,800,000		1,300,000
Capitalized Software [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite-Lived Intangible Assets	108,586,000	[1]	87,426,000	[1]
Accumulated Amortization, Finite-Lived Intangible Assets	(45,840,000)	[2]	(33,933,000)	[2]
Net Carrying Amount, Finite-Lived Intangible Assets	62,746,000		53,493,000
Customer Relationships [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite-Lived Intangible Assets	6,930,000		7,145,000
Accumulated Amortization, Finite-Lived Intangible Assets	(6,372,000)		(6,222,000)
Net Carrying Amount, Finite-Lived Intangible Assets	558,000		923,000
Patents, copyrights and trademarks [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite-Lived Intangible Assets	6,453,000		6,161,000
Accumulated Amortization, Finite-Lived Intangible Assets	(3,946,000)		(3,522,000)
Net Carrying Amount, Finite-Lived Intangible Assets	2,507,000		2,639,000
Core technology [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite-Lived Intangible Assets	4,698,000		4,856,000
Accumulated Amortization, Finite-Lived Intangible Assets	(4,698,000)		(4,856,000)
Other [Member]
Intangible Assets [Line Items]
Gross Carrying Amount, Finite-Lived Intangible Assets	1,503,000		670,000
Accumulated Amortization, Finite-Lived Intangible Assets	(1,126,000)		(636,000)
Net Carrying Amount, Finite-Lived Intangible Assets	$ 377,000		$ 34,000

[1] Includes $4.1 million of software held under a capital lease classified as capitalized software as of September 30, 2013 and December 31, 2012.

[2] Includes $1.8 million and $1.3 million of accumulated amortization of software held under a capital lease as of September 30, 2013 and December 31, 2012, respectively, which is amortized using the straight-line method over the useful life.