Derivative Instruments and Hedging Activity (Details - Designated as hedges) - Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	Jun. 28, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative, Notional Amount	$ 31,325	$ 39,714
Derivative, Fair Value, Net	746	648
Prepaid Expenses and Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	9,917	5,258
Derivative Asset, Fair Value, Gross Asset	101	239
Prepaid Expenses and Other Current Assets [Member] | Precious Metal Swaps [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	0	4,533
Derivative Asset, Fair Value, Gross Asset	0	237
Prepaid Expenses and Other Current Assets [Member] | Copper Swap [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	977	0
Derivative Asset, Fair Value, Gross Asset	9	0
Other Current Liabilities
Derivative [Line Items]
Derivative Liability, Notional Amount	20,711	34,456
Derivative Liability, Fair Value, Gross Liability	824	887
Other Current Liabilities | Precious Metal Swaps [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	6,828	2,864
Derivative Liability, Fair Value, Gross Liability	573	135
Other Current Liabilities | Copper Swap [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	4,359	11,170
Derivative Liability, Fair Value, Gross Liability	182	569
Other Noncurrent Liabilities [Member] | Precious Metal Swaps [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	697	0
Derivative Liability, Fair Value, Gross Liability	23	0
Japan, Yen | Prepaid Expenses and Other Current Assets [Member] | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative Asset, Notional Amount	1,465	0
Derivative Asset, Fair Value, Gross Asset	9	0
Japan, Yen | Other Current Liabilities | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative Liability, Notional Amount	2,065	1,264
Derivative Liability, Fair Value, Gross Liability	35	17
Euro Member Countries, Euro | Prepaid Expenses and Other Current Assets [Member] | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative Asset, Notional Amount	7,475	725
Derivative Asset, Fair Value, Gross Asset	83	2
Euro Member Countries, Euro | Other Current Liabilities | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative Liability, Notional Amount	7,459	19,158
Derivative Liability, Fair Value, Gross Liability	$ 34	$ 166