Business Acqusition Business Acquisition (Details) - USD ($) $ in Thousands			3 Months Ended								12 Months Ended
	Dec. 04, 2019	Feb. 11, 2019	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
Business Acquisition [Line Items]
Business combination, consideration transferred	$ 13,900
Payments to acquire business		$ 365,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount		215,800
Acquisition and integration costs			$ 600	$ 800	$ 1,100	$ 1,600	$ 1,900	$ 1,700	$ 3,000	$ 7,900			$ 1,100
Revenues			252,828	$ 237,835	$ 157,785	$ 214,010	264,865	$ 233,590	$ 238,263	$ 218,378	$ 862,459	$ 955,097	859,634
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		119
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables		4,587
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory		4,582
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other		146
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets		9,434
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		4,036
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets		80
Goodwill			$ 618,440				$ 618,042				618,440	618,042	400,440
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		166
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		369,509
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities		4,462
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		4,462
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		365,047
Pro Forma Information [Abstract]
Business Acquisition, Pro Forma Revenue												960,115	898,545
Business Acquisition, Pro Forma Net Income (Loss)												44,361	10,407
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	4,100
Goodwill, Acquired During Period	$ 700	$ 215,800									0	217,482
Buffalo Filter LLC [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		16 years
Revenues												49,600
Goodwill		$ 215,793
Customer Relationships [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 124,000
Customer Relationships [Member] | Buffalo Filter LLC [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		16 years
Technology-Based Intangible Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 9,000
Technology-Based Intangible Assets [Member] | Buffalo Filter LLC [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years
Trademarks and Trade Names [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 7,000
Trademarks and Trade Names [Member] | Buffalo Filter LLC [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		20 years
Selling and Administrative Expenses [Member]
Business Acquisition [Line Items]
Acquisition and integration costs											1,192	13,066	2,372
Selling and Administrative Expenses [Member] | Buffalo Filter LLC [Member]
Business Acquisition [Line Items]
Acquisition and integration costs													1,300
Cost of Sales [Member]
Business Acquisition [Line Items]
Acquisition and integration costs											$ 2,820	$ 1,335	0
Pro Forma [Member] | Selling and Administrative Expenses [Member] | Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Acquisition and integration costs													13,100
Pro Forma [Member] | Cost of Sales [Member] | Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Acquisition and integration costs													$ 1,300