Information on Business Segments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Segment	Sep. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			2
Net sales	$ 369,797	$ 357,156	$ 1,111,772	$ 1,063,451
Operating profit	59,063	48,898	179,575	155,935
Interest expense	4,054	3,748	12,078	10,638
Other expense (income), net	2,447	1,469	5,157	(3,965)
Income before income taxes	52,562	43,681	162,340	149,262
Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	125,665	116,767	372,102	343,899
Operating profit	25,734	18,562	75,571	60,818
Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	244,133	240,390	739,677	719,556
Operating profit	33,329	30,336	104,004	95,117
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net sales	$ (1)	$ (1)	$ (7)	$ (4)