Revenue Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 217,100	$ 199,830
Consumer [Member]
Disaggregation of Revenue [Line Items]
Net sales	64,730	58,880
Aerospace [Member]
Disaggregation of Revenue [Line Items]
Net sales	45,810	45,420
Industrial [Member]
Disaggregation of Revenue [Line Items]
Net sales	54,350	49,290
Oil and gas [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 52,210	$ 46,240