Information on Business Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) Segment	Mar. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	2
Net sales	$ 366,660	$ 341,802
Operating profit	56,633	56,278
Interest expense	3,892	3,349
Other expense (income), net	1,763	553
Income before income taxes	50,978	52,376
Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	120,699	114,470
Operating profit	24,255	22,375
Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	245,967	227,340
Operating profit	32,378	33,903
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net sales	$ (6)	$ (8)