Fair Value Measurements (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	$ 486	$ 2,075
Liability derivatives	(3,361)	(821)
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	0	0
Liability derivatives	0	0
Bank acceptances	0	0
Rabbi trust assets	2,812	2,947
Financial assets and financial liabilities, reported at fair value	2,812	2,947
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	486	2,075
Liability derivatives	(3,361)	(821)
Bank acceptances	11,941	14,460
Rabbi trust assets	0	0
Financial assets and financial liabilities, reported at fair value	9,066	15,714
Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	0	0
Liability derivatives	0	0
Bank acceptances	0	0
Rabbi trust assets	0	0
Financial assets and financial liabilities, reported at fair value	0	0
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Asset derivatives	486	2,075
Liability derivatives	(3,361)	(821)
Bank acceptances	11,941	14,460
Rabbi trust assets	2,812	2,947
Financial assets and financial liabilities, reported at fair value	$ 11,878	$ 18,661
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Maturity of bank acceptances	3 years
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Maturity of bank acceptances	6 months