Segment Reporting (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Operations of the Company's operating segments
Net Sales to External Customers	$ 649,162,000	$ 679,452,000
Revenue Transactions With Other Operating Segments	0	0
Net Sales	649,162,000	679,452,000
Segment Profit	141,278,000	147,841,000
Goodwill	536,895,000	535,517,000	$ 535,979,000
Us Operations segment Member
Operations of the Company's operating segments
Net Sales to External Customers	241,409,000	234,650,000
Revenue Transactions With Other Operating Segments	26,391,000	26,145,000
Net Sales	267,800,000	260,795,000
Segment profit	44,938,000	37,985,000
Goodwill	413,898,000	410,021,000
Swiss Operations segment Member
Operations of the Company's operating segments
Net Sales to External Customers	31,897,000	33,577,000
Revenue Transactions With Other Operating Segments	152,848,000	153,731,000
Net Sales	184,745,000	187,308,000
Segment profit	53,910,000	53,522,000
Goodwill	22,751,000	21,757,000
Western European Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	153,325,000	165,906,000
Revenue Transactions With Other Operating Segments	41,715,000	44,045,000
Net Sales	195,040,000	209,951,000
Segment profit	24,107,000	25,725,000
Goodwill	85,058,000	88,208,000
Chinese Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	100,599,000	121,723,000
Revenue Transactions With Other Operating Segments	48,749,000	56,857,000
Net Sales	149,348,000	178,580,000
Segment profit	45,550,000	59,484,000
Goodwill	619,000	663,000
Other Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	121,932,000	123,596,000
Revenue Transactions With Other Operating Segments	896,000	1,261,000
Net Sales	122,828,000	124,857,000
Segment profit	11,026,000	13,187,000
Goodwill	14,569,000	14,868,000
Intersegment Elimination [Member]
Operations of the Company's operating segments
Net Sales to External Customers	0	0
Revenue Transactions With Other Operating Segments	(270,599,000)	(282,039,000)
Net Sales	(270,599,000)	(282,039,000)
Segment profit	(38,253,000)	(42,062,000)
Goodwill	$ 0	$ 0