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Basis of Financial Statement Presentation - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
New Accounting Pronouncement, Early Adoption [Line Items]
Effect on revenue		$ 186,413	$ 174,879	$ 378,073	$ 340,366
Effect on retained earnings	$ 376,381	397,885		397,885		$ 374,783
Cost of sales		150,286	131,552	302,439	256,541
Selling, product development and administrative expenses		23,878	23,290	49,349	48,640
Accounting Standards Update 2014-09 \| Difference between Revenue Guidance in Effect before and after Topic 606
New Accounting Pronouncement, Early Adoption [Line Items]
Effect on revenue	19,600	1,607		7,862
Effect on retained earnings	1,598	1,899		1,899
Cost of sales		1,541		7,504
Selling, product development and administrative expenses		$ 0		$ 0
Accounting Standards Update 2017-07
New Accounting Pronouncement, Early Adoption [Line Items]
Cost of sales			100		200
Selling, product development and administrative expenses			$ 100		$ 200
Thermal Acoustical Solutions \| Accounting Standards Update 2014-09 \| Difference between Revenue Guidance in Effect before and after Topic 606
New Accounting Pronouncement, Early Adoption [Line Items]
Effect on revenue	$ 16,300