Retirement Plans and Postretirement Medical Benefits (Estimated Amounts to be Amortized from AOCI into Net Periodic Benefit) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Nonpension postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 5,438
Prior service credit	297
Total	5,735
United States
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	26,824
Prior service credit	(60)
Transition asset	0
Total	26,764
Foreign
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	5,804
Prior service credit	(66)
Transition asset	(9)
Total	$ 5,729