Pension and Other Postretirement Benefits (Details 6) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Total	[1]	$ 15,426	$ (10,726)	$ 8,867
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost		(669)
Net loss		(29,108)
Amortization of prior service costs (credits)		423
Amortization of actuarial loss		8,878
Foreign exchange rate changes		821
Amounts reclassified from accumulated other comprehensive income to retained earnings		(18,313)
Total		(37,968)
Other postretirement benefit plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost		0
Net loss		3,800
Amortization of prior service costs (credits)		15
Amortization of actuarial loss		428
Foreign exchange rate changes		(14)
Amounts reclassified from accumulated other comprehensive income to retained earnings		(1,107)
Total		$ 3,122

[1] Net of tax of $(4,606), $4,469 and $(4,687) for the years ended December 31, 2018, 2017 and 2016, respectively.