Information on Business Segments Details 1 (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Assets	$ 2,416,196	$ 2,365,716
Aerospace [Member]
Segment Reporting Information [Line Items]
Assets	675,741	667,085
Industrial [Member]
Segment Reporting Information [Line Items]
Assets	1,574,386	1,505,355
Other [Member]
Segment Reporting Information [Line Items]
Assets	$ 166,069	$ 193,276