Retirement Plans - Components of Prepaid (Accrued) Cost (Details 3) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
U.S.Pension Plans
Retirement Plans
Prepaid pension asset	$ 33,779	$ 31,581
Other accrued liabilities	0	0
Post-retirement obligations	(1,388)	(1,493)
Components of prepaid (accrued) cost, net	32,391	30,088
Non-U.S. Pension Plans
Retirement Plans
Prepaid pension asset	0	518
Other accrued liabilities	0	0
Post-retirement obligations	(1,316)	(1,558)
Components of prepaid (accrued) cost, net	(1,316)	(1,040)
Other Post-Retirement Benefit Plan
Retirement Plans
Other accrued liabilities	(358)	(342)
Post-retirement obligations	(4,528)	(4,852)
Components of prepaid (accrued) cost, net	$ (4,886)	$ (5,194)