Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 690,673	$ 731,366	$ 1,339,835	$ 1,410,818
Contract with Customer, Asset, after Allowance for Credit Loss	24,800		24,800		$ 17,400
Americas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	270,291	292,345	535,124	550,978
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	194,165	207,309	388,992	416,864
Asia [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	226,217	231,712	415,719	442,976
Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	537,113	565,927	1,026,447	1,090,274
Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	112,287	127,990	232,251	247,932
Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 41,273	37,449	$ 81,137	72,612
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	$ 359,471	379,659	$ 716,562	739,392
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	$ 288,824	303,059	$ 541,179	574,379
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	$ 42,378	48,648	$ 82,094	97,047
US Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	249,340	267,889	490,750	502,540
US Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	188,363	202,608	365,799	376,864
US Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	46,342	53,054	96,577	102,707
US Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	14,635	12,227	28,374	22,969
Swiss Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	28,948	31,358	60,844	64,935
Swiss Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	22,012	24,362	46,288	51,027
Swiss Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,726	5,035	10,282	9,985
Swiss Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,210	1,961	4,274	3,923
Western European Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	149,051	163,681	302,376	329,587
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	104,458	115,195	210,335	231,751
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	27,945	32,553	59,336	65,328
Western European Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	16,648	15,933	32,705	32,508
Chinese Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	140,907	136,459	241,506	258,181
Chinese Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	128,151	124,042	218,472	235,457
Chinese Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,784	9,548	16,890	17,252
Chinese Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,972	2,869	6,144	5,472
Other Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	122,427	131,979	244,359	255,575
Other Operations [Member] | Product [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	94,129	99,720	185,553	195,175
Other Operations [Member] | Service [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	23,490	27,800	49,166	52,660
Other Operations [Member] | Service [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 4,808	$ 4,459	$ 9,640	$ 7,740