Segment Reporting Revenues by Division - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Sales Information
Revenue from Contract with Customer, Excluding Assessed Tax									$ 3,085,177	$ 3,008,652	$ 2,935,586
Revenues	$ 937,985	$ 807,357	$ 690,673	$ 649,162	$ 843,968	$ 753,866	$ 731,366	$ 679,452	3,085,177	3,008,652	2,935,586
Laboratory products and services [Member]
Segment Sales Information
Revenue from Contract with Customer, Excluding Assessed Tax									1,669,791
Revenues										1,578,625	1,504,600
Industrial products and services [Member]
Segment Sales Information
Revenue from Contract with Customer, Excluding Assessed Tax									1,224,497
Revenues										1,233,970	1,211,362
Retail products and services [Member]
Segment Sales Information
Revenue from Contract with Customer, Excluding Assessed Tax									$ 190,889
Revenues										$ 196,057	$ 219,624