Purchased Intangible Assets and Goodwill (Changes in Purchased Intangibles Balances) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Intangible Assets [Roll Forward]
Beginning balance	$ 21,200	$ 23,134
Amortization	(1,069)	(1,189)	(1,300)
Disposal, related to sale of Traex assets	0	(643)
Foreign currency impact	(91)	102
Ending balance	$ 20,222	$ 21,200	$ 23,134