Income Taxes Deferred Tax Reconciliation (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Reconciliation [Abstract]
Deferred Tax Assets, Tax Credit Carryforwards, Research	$ 16,200
Deferred Tax Liabilities, Undistributed Foreign Earnings	1,300
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Warranty Reserves	919	$ 937
Deferred Tax Assets, Inventory	2,697	1,731
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Restructuring Charges	5	58
Deferred Tax Assets, Operating Loss Carryforwards	59,784	61,521
Deferred Tax Assets, Tax Credit Carryforwards	22,817	23,866
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	2,142	2,042
Deferred Tax Assets, Property, Plant and Equipment	952	950
Deferred Tax Assets, Goodwill and Intangible Assets	2,109	2,516
Deferred Tax Assets, Other	5,693	4,056
Deferred Tax Assets, Gross	97,118	97,677
Deferred Tax Assets, Valuation Allowance	(86,752)	(84,240)
Deferred Tax Assets, Net of Valuation Allowance	10,366	13,437
Deferred Tax Liabilities, Intangible Assets	(7,582)	(11,764)
Deferred Tax Liabilities, Other	(1,611)	(593)
Deferred Tax Liabilities, Net	(9,193)	(12,357)
Deferred Tax Assets, Net	1,173	$ 1,080
Undistributed Earnings of Foreign Subsidiaries	$ 3,800