Intangible Assets (Schedule Of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 14,182	$ 14,160
Accumulated Amortization	(8,097)	(7,698)
Net Carrying Value	6,085	6,463
Weighted Average Useful Life (in Years)	3 years 3 months 18 days	3 years 6 months
Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,159	8,152
Accumulated Amortization	(4,865)	(4,587)
Net Carrying Value	3,294	3,566
Weighted Average Useful Life (in Years)	3 years 4 months 24 days	3 years 7 months 6 days
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,267	3,267
Accumulated Amortization	(2,174)	(2,110)
Net Carrying Value	1,093	1,157
Weighted Average Useful Life (in Years)	4 years 3 months 18 days	4 years 6 months
Other Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,889	1,874
Accumulated Amortization	(1,058)	(1,001)
Net Carrying Value	831	873
Weighted Average Useful Life (in Years)	2 years 10 months 24 days	3 years 1 month 6 days
Software Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	867	867
Net Carrying Value	$ 867	$ 867
Weighted Average Useful Life (in Years)	3 years	3 years