Purchased Intangible Assets and Goodwill (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization	$ (1,069)	$ (1,189)	$ (1,300)
Definite life intangible assets, weighted average remaining life	7 years 4 months 24 days
Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Definite life intangible assets, amortization period	13 years
Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Definite life intangible assets, amortization period	20 years