Information on Business Segments Details 1 (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Assets	$ 2,362,900	$ 2,365,716
Aerospace [Member]
Segment Reporting Information [Line Items]
Assets	689,830	667,085
Industrial [Member]
Segment Reporting Information [Line Items]
Assets	1,493,998	1,505,355
Other [Member]
Segment Reporting Information [Line Items]
Assets	$ 179,072	$ 193,276