Summary of Operations and Significant Accounting Policies (Summary of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 25,565	$ 25,515
Accumulated Amortization	10,718	9,834
Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	18,533	18,533
Weighted average useful life	3 years 9 months 18 days	3 years 9 months 18 days
Accumulated Amortization	6,341	5,904
Customer Contracts [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,061	5,061
Weighted average useful life	3 years 6 months	3 years 6 months
Accumulated Amortization	2,816	2,485
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	725	725
Weighted average useful life	2 years 8 months 12 days	2 years 8 months 12 days
Accumulated Amortization	692	644
Non-compete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	486	486
Weighted average useful life	1 year 2 months 12 days	1 year 2 months 12 days
Accumulated Amortization	459	421
Patents [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	475	475
Weighted average useful life	11 years	11 years
Accumulated Amortization	167	145
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	285	235
Weighted average useful life	3 years	3 years
Accumulated Amortization	$ 243	$ 235