Summary of Disaggregation of Product Revenues from Contracts with Customers by Major Product Line (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 69,474	$ 69,445	$ 70,692	$ 60,634	$ 51,942	$ 49,529	$ 47,731	$ 44,830	$ 270,245		$ 194,032	$ 141,236
Product
Disaggregation of Revenue [Line Items]
Revenue									270,097	[1]	193,891	141,089	[2]
Royalty and Other Revenue
Disaggregation of Revenue [Line Items]
Revenue									$ 148		$ 141	$ 147

[1] 2019 revenue for process analytics products includes revenue related to C Technologies from May 31, 2019 through December 31, 2019.

[2] 2017 revenue for filtration, chromatography and other products includes revenue related to Spectrum from August 1, 2017 through December 31, 2017.