Borrowing Facilities (Details) $ in Thousands, THB in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 THB	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Nov. 12, 2015 USD ($)
Line of Credit Facility [Line Items]
Credit Agreement maturity date				Nov. 12, 2020
Principal amount					$ 214,172	$ 226,568
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Credit Agreement capacity					430,000
Credit agreement, secured by percentage of stock of the Company's domestic subsidiaries				100.00%
Credit agreement, secured by percentage of voting capital stock of each direct foreign subsidiary				65.00%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Agreement capacity					200,000
Term period				5 years
Credit Agreement maturity date				Nov. 12, 2020
Possible increase to total commitments under Credit Agreement					150,000
Letters of credit outstanding amount					2,600
Revolving credit facility, available for future borrowings					197,400
Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Term period				5 years
Credit Agreement maturity date				Nov. 12, 2020
Term Loan proceeds							$ 230,000
Term Loan frequency of periodic payments				quarterly
Derivative Notional Amount					155,300
Principal amount					207,000
Term Loan Facility [Member] | Interest Rate Swap [Member]
Line of Credit Facility [Line Items]
Derivative Notional Amount					155,300
Term Loan Facility [Member] | Scenario Forecast [Member]
Line of Credit Facility [Line Items]
Quarterly principal installments	$ 8,600	$ 5,800	$ 4,300
Standby Letters Of Credit [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, available for future borrowings					20,000
Foreign currencies [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, available for future borrowings					$ 20,000
Thailand Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Agreement maturity date				Oct. 31, 2018
Benchmark Electronics (Thailand) Public Company Limited [Member] | Thailand Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Agreement capacity | THB				THB 350
Minimum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
U.S. Credit facility, commitment fee				0.30%
Maximum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
U.S. Credit facility, commitment fee				0.40%
LIBOR Plus [Member] | Minimum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate				1.25%
LIBOR Plus [Member] | Maximum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate				2.25%
Alternate Base Rate Plus [Member] | Minimum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate				0.25%
Alternate Base Rate Plus [Member] | Maximum [Member] | Credit Agreement [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate				1.25%