Income Taxes (Details 4) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Asset
Depreciation and amortization	$ 0	$ 6,616
Expense accruals	18,827	17,690
Inventories	3,071	4,390
Provision for receivables	690	649
Operating loss carryforwards	83,168	90,193
Foreign tax credit carryforwards	25,814	27,256
Capital loss carryforwards	9,759	11,011
Pensions	40,442	47,153
Currency adjustments	3,795	7,160
Post-retirement benefits	471	403
Stock based compensation	5,832	4,761
Other	5,886	7,684
Subtotal	197,755	224,966
Valuation allowance	(138,862)	(174,227)
Total deferred income taxes	58,893	50,739
Liability
Depreciation and amortization	8,681	0
Deferred revenue	3,122	979
Deferred financing costs	2,227	2,135
Total deferred income taxes	14,030	3,114
Deferred Tax Assets, Net, Classification [Abstract]
Deferred income tax assets	49,114	51,574
Other liabilities	$ 4,251	$ 3,949