Discontinued Operations (Reconciliation of Purchase Price) (Details) $ in Thousands	Dec. 19, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale, net of income taxes	$ 5,411
Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase price	55,055
Adjustments to purchase price	(791)
Amounts held in escrow	859
Payment of withholding taxes	3,492
Cash proceeds received	49,913
Transaction expenses	(2,099)
Net cash proceeds received	47,814
Net assets of high voltage product line	(56,718)
Release of accumulated other comprehensive income from equity	10,120
Release of withholding tax liabilities	890
Release of employee liabilities and cancellation of equity awards	488
Gain on sale of high voltage product line, before income taxes	6,945
Income tax related to gain on sale	$ (1,534)