Segment Information (Net Sales By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Information [Line Items]
Net sales	$ 702,789	$ 662,552
Operating Segments [Member] | Petroleum Additives [Member]
Segment Information [Line Items]
Net sales	699,991	660,304
Operating Segments [Member] | All Other [Member]
Segment Information [Line Items]
Net sales	2,798	2,248
Operating Segments [Member] | Lubricant Additives [Member] | Petroleum Additives [Member]
Segment Information [Line Items]
Net sales	602,574	570,042
Operating Segments [Member] | Fuel Additives [Member] | Petroleum Additives [Member]
Segment Information [Line Items]
Net sales	$ 97,417	$ 90,262