Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
U.S. Deferred tax benefit	$ 7,628	$ 7,422	$ 8,390
Effect of Tax Cuts and Jobs Act [Abstract]
Tax Cuts and Jobs Act, Transition Tax for Accumulated Foreign Earnings Liability	63,800
Tax Cuts and Jobs Act, Transition Tax for Accumulated Foreign Earnings Liability NonCurrent	58,400
Tax Cuts and Jobs Act, Income Tax Expense (Benefit)	(6,400)	101,600
Revaluation of deferred tax assets and liabilities	2,000	(3,900)
Provisional impact of U.S. Tax Reform	(4,353)	97,707	0
Global Intangible Low-Taxed Income	3,206	0	0
Foreign earnings repatriated	560,600
Income tax expense on foreign earnings expected to be repatriated	21,612	0	0
Net change in total deferred tax asset valuation allowance	2,100	200	1,200
Cumulative undistributed earnings of foreign subsidiaries	330,000
Income tax incentives	$ 7,886	$ 7,238	$ 6,716
Net impact of tax incentives, per diluted share	$ 0.17	$ 0.15	$ 0.13
Unrecognized tax benefits including interest and penalties	$ 400
Interest on unrecognized tax	100
Penalty on unrecognized tax	17
Interest and penalties included in income tax expense	100	$ 0	$ 0
Additional reserve for uncertain tax benefits	0	894	89
Decrease in unrecognized tax benefits reserve due to expiration of statute of limitations	0	0	(5,079)
Decreases related to prior year tax positions	532	8,197	333
Unrecognized deferred tax liability	2,300
U.S. Federal [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Provisional impact of U.S. Tax Reform	4,400
Income Tax Reconciliation Tax Credits Foreign	9,200
Operating loss carryforwards	$ 24,400
U.S. Federal [Member] | Earliest Tax Year [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Operating loss carryforwards expiration Year	2025
U.S. Federal [Member] | Latest Tax Year [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Operating loss carryforwards expiration Year	2036
State and local [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Operating loss carryforwards	$ 67,000
Tax credit carryforward	$ 1,900
State and local [Member] | Earliest Tax Year [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Operating loss carryforwards expiration Year	2019
State and local [Member] | Latest Tax Year [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Operating loss carryforwards expiration Year	2031
Tax credit carryforward expiration year	2036
Foreign [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Income tax expense on foreign earnings expected to be repatriated	$ 30,800
Operating loss carryforwards	20,500
Foreign operating loss with indefinited carry forward period	$ 24,800
Foreign [Member] | Latest Tax Year [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Operating loss carryforwards expiration Year	2028
China [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Income tax incentives	$ 1,884	1,398	1,302
Malaysia [Member}
Effect of Tax Cuts and Jobs Act [Abstract]
Income tax incentives	3,287	4,295	2,346
Thailand [Member]
Effect of Tax Cuts and Jobs Act [Abstract]
Income tax incentives	2,715	$ 1,545	$ 3,068
Decreases related to prior year tax positions	$ 7,300