Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 807,357	$ 753,866	$ 2,147,192	$ 2,164,684
Contract with Customer, Asset, after Allowance for Credit Loss	29,400		29,400		$ 17,400
Americas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	304,963	298,304	840,087	849,282
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	232,133	212,736	621,126	629,600
Asia [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	270,261	242,826	685,979	685,802
Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	630,372	586,756	1,656,819	1,677,030
Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	132,864	127,854	365,115	376,266
Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 44,121	39,256	$ 125,258	111,388
Laboratory products and services [Member]
Disaggregation of Revenue [Line Items]
Percentage of Disaggregated Revenue in Relationship to Segments	54.00%		54.00%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 430,516	388,441	$ 1,147,078	1,127,833
Industrial products and services [Member]
Disaggregation of Revenue [Line Items]
Percentage of Disaggregated Revenue in Relationship to Segments	40.00%		40.00%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 322,808	315,337	$ 863,987	889,716
Retail products and services [Member]
Disaggregation of Revenue [Line Items]
Percentage of Disaggregated Revenue in Relationship to Segments	6.00%		6.00%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 54,033	50,088	$ 136,127	147,135
US Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	278,948	269,038	769,696	771,578
US Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	212,607	203,291	578,405	580,155
US Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	52,000	53,035	148,577	156,221
US Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	14,341	12,712	42,714	35,202
Swiss Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	38,848	33,415	99,693	98,350
Swiss Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	30,507	26,114	76,796	77,142
Swiss Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	6,329	5,191	16,611	15,176
Swiss Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,012	2,110	6,286	6,032
Western European Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	177,630	168,652	480,006	498,240
Western European Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	124,073	120,510	334,408	352,260
Western European Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	34,519	31,852	93,855	97,182
Western European Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	19,038	16,290	51,743	48,798
Chinese Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	165,231	142,292	406,738	400,473
Chinese Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	150,879	129,163	369,351	364,620
Chinese Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	11,414	10,111	28,304	27,363
Chinese Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,938	3,018	9,083	8,490
Other Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	146,700	140,469	391,059	396,043
Other Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	112,306	107,678	297,859	302,853
Other Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28,602	27,665	77,768	80,324
Other Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 5,792	$ 5,126	$ 15,432	$ 12,866