CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Revenue:
Revenue	$ 366,260		$ 270,245		$ 194,032
Costs and operating expenses:
Cost of product revenue	156,634		119,099		86,531
Research and development	20,182		19,450		15,821
Selling, general and administrative	119,621		95,613		65,692
Total costs and operating expenses	296,437		234,162		168,044
Income from operations	69,823		36,083		25,988
Other (expenses) income:
Investment income	1,741		5,324		1,895
Loss on extinguishment of debt			(5,650)
Interest expense	(12,133)		(9,292)		(6,709)
Other (expenses) income	(214)		(314)		262
Other expenses, net	(10,606)		(9,932)		(4,552)
Income before income taxes	59,217		26,151		21,436
Income tax (benefit) provision	(709)		4,740		4,819
Net income	$ 59,926		$ 21,411		$ 16,617
Earnings per share:
Basic	$ 1.14		$ 0.44		$ 0.38
Diluted	$ 1.11		$ 0.44		$ 0.37
Weighted average common shares outstanding:
Basic	52,554		48,343		43,767
Diluted	53,892		49,206		45,471
Net income	$ 59,926		$ 21,411		$ 16,617
Other comprehensive income (loss):
Foreign currency translation adjustment	17,112		(3,134)		(5,530)
Comprehensive income	77,038		18,277		11,087
Products
Revenue:
Revenue	366,136	[1]	270,097	[2]	193,891
Royalty and Other Revenue
Revenue:
Revenue	$ 124		$ 148		$ 141

[1] 2020 revenue for filtration products includes revenue related to EMT from July 13, 2020, NMS from October 20, 2020 and ARTeSYN from December 3, 2020.

[2] 2019 revenue includes process analytics revenue related to C Technologies from June 1, 2019 through December 31, 2019.