Information on Business Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 1,230,754	$ 1,193,975	$ 1,262,006
Operating profit	192,178	168,396	179,974
Assets	2,137,539	2,061,866	2,073,900
Depreciation and amortization	80,154	78,242	81,395
Capital expenditures	47,577	45,982	57,365
Interest expense	11,883	10,698	11,392
Other expense (income), net	(2,326)	(248)	2,082
Income from continuing operations before income taxes	$ 182,621	$ 157,946	$ 166,500
General Electric [Member]
Segment Reporting Information [Line Items]
Revenue by major customer	17.00%	18.00%	19.00%
Aerospace [Member]
Segment Reporting Information [Line Items]
Revenues	$ 406,500	$ 411,700	$ 440,000
Operating profit	62,500	65,400	71,600
Assets	647,800	654,100	655,000
Depreciation and amortization	30,000	30,800	24,900
Capital expenditures	21,100	17,200	20,900
Industrial [Member]
Segment Reporting Information [Line Items]
Revenues	824,200	782,300	822,100
Operating profit	129,700	103,000	108,400
Assets	1,356,100	1,241,200	1,282,000
Depreciation and amortization	49,500	46,000	54,700
Capital expenditures	25,900	28,700	36,100
Other [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0
Operating profit	0	0	0
Assets	133,700	166,500	136,900
Depreciation and amortization	700	1,300	1,800
Capital expenditures	$ 500	$ 100	$ 400