Contingencies - Accrual for Environmental Remediation (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Environmental remediation accrual at December 31, 2014	$ 266
Payments	(186)
Environmental remediation accrual at September 30, 2015	80
Bridgeport, CT
Environmental remediation accrual at December 31, 2014	6
Payments	(6)
Environmental remediation accrual at September 30, 2015	0
Fremont, NC
Environmental remediation accrual at December 31, 2014	260
Payments	(180)
Environmental remediation accrual at September 30, 2015	$ 80