Income Taxes (Reconciliation Of The Statutory Federal Income Tax Rate To The Company's Effective Tax Rate On Earnings) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Statutory rate (as a percent)	21.00%	35.00%	35.00%
State income taxes, net of federal tax benefit (as a percent)	0.30%	1.70%	1.40%
Foreign earnings taxed at rates other than the U.S. statutory rate (as a percent)	(1.50%)	(4.70%)	(4.40%)
Foreign currency remeasurement (as a percent)	(1.90%)	(0.70%)	2.20%
Income tax adjustments to filed returns (as a percent)	(1.90%)	(3.00%)	0.80%
Biodiesel credit (as a percent)	(2.30%)	(0.00%)	(3.30%)
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Percent	(0.00%)	(2.20%)	(1.40%)
Effective Income Tax Rate Reconciliation, GILTI, as a Percent	1.00%
Effective Income Tax Rate Reconciliation, Foreign Derived Intangible Income Deduction, as a Percent	(1.00%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	1.10%	23.90%
Valuation allowance (as a percent)	0.00%	0.30%	0.60%
Other (as a percent)	(0.70%)	(2.10%)	(1.60%)
Effective income tax rate	11.90%	0.40%	29.30%