Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 679,452	$ 660,821
Americas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	258,631	252,279
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	209,555	205,840
Total Asia Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 211,266	202,702
Laboratory Related Products and Services [Member]
Disaggregation of Revenue [Line Items]
Percentage of Disaggregated Revenue in Relationship to Segments	53.00%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 359,732	345,159
Product Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 524,347	510,946
Industrial Related Products and Services [Member]
Disaggregation of Revenue [Line Items]
Percentage of Disaggregated Revenue in Relationship to Segments	40.00%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 271,320	262,656
Retail Related Products and Services [Member]
Disaggregation of Revenue [Line Items]
Percentage of Disaggregated Revenue in Relationship to Segments	7.00%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 48,400	53,006
Service Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	120,263	118,403
Service Revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	34,842	31,472
Us Operations segment Member
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	234,650	229,745
Us Operations segment Member | Product Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	174,256	172,501
Us Operations segment Member | Service Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	49,651	47,619
Us Operations segment Member | Service Revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	10,743	9,625
Swiss Operations segment Member
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	33,577	32,466
Swiss Operations segment Member | Product Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	26,665	25,565
Swiss Operations segment Member | Service Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,951	4,830
Swiss Operations segment Member | Service Revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,961	2,071
Western European Operations Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	165,906	165,372
Western European Operations Segment [Member] | Product Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	116,555	116,932
Western European Operations Segment [Member] | Service Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	33,939	34,590
Western European Operations Segment [Member] | Service Revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	15,412	13,850
Chinese Operations Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	121,723	113,930
Chinese Operations Segment [Member] | Product Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	111,416	104,292
Chinese Operations Segment [Member] | Service Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	7,704	7,127
Chinese Operations Segment [Member] | Service Revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,603	2,511
Other Operations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	123,596	119,308
Other Operations [Member] | Product Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	95,455	91,656
Other Operations [Member] | Service Revenue [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	24,018	24,237
Other Operations [Member] | Service Revenue [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 4,123	$ 3,415