Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Operations of the Company's operating segments
Net Sales to External Customers	$ 608,286	$ 582,057	$ 1,147,960	$ 1,117,758
Revenue Transactions With Other Operating Segments	0	0	0	0
Total net sales	608,286	582,057	1,147,960	1,117,758
Segment Profit	129,077	118,310	231,090	215,616
Goodwill	444,278	442,482	444,278	442,482	$ 446,284
US Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	216,968	204,263	404,903	383,086
Revenue Transactions With Other Operating Segments	22,102	22,840	41,733	41,132
Total net sales	239,070	227,103	446,636	424,218
Segment profit	41,112	37,101	70,267	61,417
Goodwill	319,715	308,863	319,715	308,863
Swiss Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	30,720	33,153	57,685	64,004
Revenue Transactions With Other Operating Segments	126,983	116,753	247,294	233,093
Total net sales	157,703	149,906	304,979	297,097
Segment profit	34,997	33,359	70,819	69,534
Goodwill	22,105	23,198	22,105	23,198
Western European Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	154,264	148,803	291,915	289,721
Revenue Transactions With Other Operating Segments	38,945	38,357	77,492	79,307
Total net sales	193,209	187,160	369,407	369,028
Segment profit	24,303	22,777	44,493	42,783
Goodwill	87,452	96,552	87,452	96,552
Chinese Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	92,886	91,013	177,833	177,461
Revenue Transactions With Other Operating Segments	58,655	54,711	104,581	103,180
Total net sales	151,541	145,724	282,414	280,641
Segment profit	45,934	41,386	82,560	74,613
Goodwill	672	746	672	746
Other Operations [Member]
Operations of the Company's operating segments
Net Sales to External Customers	113,448	104,825	215,624	203,486
Revenue Transactions With Other Operating Segments	1,700	1,588	3,054	2,945
Total net sales	115,148	106,413	218,678	206,431
Segment profit	13,249	10,066	24,343	19,188
Goodwill	14,334	13,123	14,334	13,123
Intersegment Elimination [Member]
Operations of the Company's operating segments
Net Sales to External Customers	0	0	0	0
Revenue Transactions With Other Operating Segments	(248,385)	(234,249)	(474,154)	(459,657)
Total net sales	(248,385)	(234,249)	(474,154)	(459,657)
Segment profit	(30,518)	(26,379)	(61,392)	(51,919)
Goodwill	$ 0	$ 0	$ 0	$ 0