Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Accrued expenses and reserves	$ 1,475	$ 2,035
Postretirement and postemployment benefits	800	924
Employee benefits	2,691	2,838
Operating lease liabilities	5,269
Inventories	1,410	1,261
Other assets	1,128	1,285
Interest disallowance	11,686	6,157
Operating loss and credit carryforwards	12,806	14,782
Gross deferred tax assets	37,265	29,282
Less valuation allowance	(16,553)	(3,828)
Deferred tax assets	20,712	25,454
Deferred tax liabilities
Property, plant and equipment	(6,530)	(14,941)
Right-of-use operating lease assets	(4,619)
Intangible assets and other liabilities	(14,790)	(25,801)
Foreign investments	(1,026)	(1,261)
Deferred tax liabilities	(26,965)	(42,003)
Net deferred tax liability	(6,253)	(16,549)
Deferred income taxes	1,281	1,064
Deferred income taxes	(7,534)	(17,613)
Net amount recognized	$ 6,253	$ 16,549