Goodwill and Intangible Assets (Summary of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 25,565	$ 25,515
Accumulated Amortization	(11,409)	(9,834)
Net Carrying Amount	14,156	15,681
Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	18,533	18,533
Weighted Average Amortization Period	3 years 9 months 18 days	3 years 9 months 18 days
Accumulated Amortization	(6,808)	(5,904)
Net Carrying Amount	11,725	12,629
Customer Contracts [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,061	5,061
Weighted Average Amortization Period	3 years 6 months	3 years 6 months
Accumulated Amortization	(2,982)	(2,485)
Net Carrying Amount	2,079	2,576
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	725	725
Weighted Average Amortization Period	2 years 8 months 12 days	2 years 8 months 12 days
Accumulated Amortization	(716)	(644)
Net Carrying Amount	9	81
Non-compete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	486	486
Weighted Average Amortization Period	1 year 2 months 12 days	1 year 2 months 12 days
Accumulated Amortization	(478)	(421)
Net Carrying Amount	8	65
Patents [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	475	475
Weighted Average Amortization Period	11 years	11 years
Accumulated Amortization	(178)	(145)
Net Carrying Amount	297	330
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	285	235
Weighted Average Amortization Period	3 years	3 years
Accumulated Amortization	(247)	(235)
Net Carrying Amount	$ 38	$ 0