Pension and Other Postretirement Benefits (Details 6) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	[1]	$ 8,867	$ (9,586)	$ 42,016
Defined benefit pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost		(1,334)
Net loss		(18,378)
Amortization of prior service costs (credits)		142
Amortization of actuarial loss		7,030
Foreign exchange rate changes		1,378
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax		(11,162)
Other postretirement benefit plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost		0
Net loss		2,194
Amortization of prior service costs (credits)		(234)
Amortization of actuarial loss		332
Foreign exchange rate changes		3
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax		$ 2,295

[1] Net of tax of $(4,687), $3,916 and $(24,799) for the years ended December 31, 2016, 2015 and 2014, respectively.