Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Loss Contingencies [Line Items]
Standard Product Warranty Accrual		$ 1,406	$ 1,654	$ 700
Product Warranty Accrual, Warranties Issued	2,482	1,987	2,363
Product Warranty Accrual, Additions from Business Acquisition	225	0	0
Product Warranty Expense	(2,089)	(2,235)	(1,409)
Product Warranty Accrual, Payments	2,024	1,406	1,654
Operating Leases, Rent Expense	3,134	3,139	2,916
Operatingleases,equipment	123	111	118
Operating Leases, Future Minimum Payments Due	3,424
Operating Leases, Future Minimum Payments, Due in Two Years	2,336
Operating Leases, Future Minimum Payments, Due in Three Years	3,198
Operating Leases, Future Minimum Payments, Due in Four Years	2,135
Operating Leases, Future Minimum Payments, Due in Five Years	2,003
Operating Leases, Future Minimum Payments, Due Thereafter	2,671
Royalty Expense	1,165	1,086	871
Purchase Commitment, Remaining Minimum Amount Committed	$ 22,058