Information on Business Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) Segment	Jun. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			2
Net sales	$ 375,315	$ 364,493	$ 741,975	$ 706,295
Operating profit	63,879	50,759	120,512	107,037
Interest expense	4,133	3,541	8,025	6,890
Other expense (income), net	947	(5,987)	2,710	(5,434)
Income before income taxes	58,799	53,205	109,777	105,581
Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	125,739	112,662	246,437	227,132
Operating profit	25,563	19,876	49,818	42,252
Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	249,577	251,845	495,544	479,185
Operating profit	38,316	30,883	70,694	64,785
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net sales	$ (1)	$ (14)	$ (6)	$ (22)