Goodwill and Intangible Assets - Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross	$ 45,281	$ 33,586
Accumulated amortization	(19,442)	(16,319)
Net	25,839	17,267
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	7 years 4 months
Gross	7,273	4,442
Accumulated amortization	(46)	(14)
Net	7,227	4,428
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	4 years 11 months
Weighted Average Useful Life (years)	6 years
Gross	18,702	13,747
Accumulated amortization	(10,163)	(8,437)
Net	8,539	5,310
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years 5 months
Gross	7,837	4,071
Accumulated amortization	(2,433)	(2,181)
Net	5,404	1,890
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	4 years 2 months
Gross	10,900	10,900
Accumulated amortization	(6,359)	(5,269)
Net	4,541	5,631
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	1 year 10 months
Gross	569	426
Accumulated amortization	(441)	(418)
Net	$ 128	$ 8