Pension and Severance Plans (Korean Severance Plan) (Details) - Korean Severance Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred Compensation Liability, Current and Noncurrent [Roll Forward]
Balance at January 1	$ 98,162	$ 127,547	$ 142,298
Provision of severance benefits	6,144	6,542	1,306
Severance payments (1)	(22,775)	(42,457)	(10,659)
Foreign currency (gain) loss	(8,186)	6,530	(5,398)
Balance at the end of year	73,345	98,162	127,547
Payments remaining with the National Pension Fund	(138)	(158)	(161)
Total accrued severance plan obligations at December 31	73,207	98,004	127,386
Less current portion of accrued severance plan obligations (Note 10)	8,194	10,837	13,408
Non-current portion of accrued severance plan obligations	$ 65,013	$ 87,167	$ 113,978